build(ci): upgrade GitHub Actions to @v5 + drop Node 20 from matrix

Addresses the Node.js 20 deprecation warning observed on every job
log:

  Node.js 20 actions are deprecated. The following actions are running
  on Node.js 20 and may not work as expected: actions/checkout@v4,
  actions/setup-node@v4, actions/upload-artifact@v4. Actions will be
  forced to run with Node.js 24 by default starting June 2nd, 2026.
  Node.js 20 will be removed from the runner on September 16th, 2026.

Bumped across every workflow:
  actions/checkout@v4         → @v5
  actions/setup-node@v4       → @v5
  actions/upload-artifact@v4  → @v5
  actions/cache@v4            → @v5

Files touched:
  .github/workflows/ci.yml
  .github/workflows/coverage.yml
  .github/workflows/browser-matrix-nightly.yml
  .github/workflows/e2e-playwright.yml
  .github/workflows/build-artifacts.yml

Also dropped Node 20.x from the ci.yml matrix. Node 20 left active
LTS in April 2026 (this month). Matrix is now [22.x, 24.x] —
active LTS + current — which halves the matrix cost (6 → 4 jobs)
and stays forward-looking.

Matrix change is ci.yml only; e2e-playwright + coverage +
build-artifacts pin 22.x explicitly and are unchanged.

Refs: #24
Track: adopt-lightpanda

Author: jadb

.github/workflows/browser-matrix-nightly.yml

@@ -37,9 +37,9 @@ jobs:
         browser_channel: [chrome, chromium, brave, edge]
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v5
         with:
           node-version: "22.x"
           cache: npm
@@ -59,7 +59,7 @@ jobs:
           sudo apt-get update -qq && sudo apt-get install -y brave-browser
 
       - name: Cache Playwright browsers
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         id: pw-cache
         with:
           path: ~/.cache/ms-playwright
@@ -87,9 +87,9 @@ jobs:
         browser_channel: [chrome, brave, edge]
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v5
         with:
           node-version: "22.x"
           cache: npm
@@ -102,7 +102,7 @@ jobs:
         run: brew install --cask brave-browser
 
       - name: Cache Playwright browsers
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         id: pw-cache
         with:
           path: ~/Library/Caches/ms-playwright
@@ -168,9 +168,9 @@ jobs:
         browser_channel: [chrome, edge]
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v5
         with:
           node-version: "22.x"
           cache: npm
@@ -179,7 +179,7 @@ jobs:
         run: npm ci
 
       - name: Cache Playwright browsers
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         id: pw-cache
         with:
           path: "%LOCALAPPDATA%\\ms-playwright"

.github/workflows/build-artifacts.yml

@@ -20,9 +20,9 @@ jobs:
         os: [ubuntu-latest, macos-latest, windows-latest]
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v5
         with:
           node-version: "22.x"
           cache: npm
@@ -36,7 +36,7 @@ jobs:
         run: npm run build
 
       - name: Upload dist artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v5
         with:
           name: dist-${{ matrix.os }}
           path: dist/

.github/workflows/ci.yml

@@ -19,14 +19,16 @@ jobs:
       matrix:
         # Cross-platform smoke: Linux is primary; macOS and Windows catch
         # platform-specific path/binary issues early.
+        # Node 20 left active LTS in April 2026 — test 22 (active LTS)
+        # and 24 (current). Drop 20 to halve matrix cost.
         os: [ubuntu-latest, macos-latest, windows-latest]
-        node: ["20.x", "22.x"]
+        node: ["22.x", "24.x"]
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
       - name: Setup Node ${{ matrix.node }}
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v5
         with:
           node-version: ${{ matrix.node }}
           cache: npm

.github/workflows/coverage.yml

@@ -14,9 +14,9 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v5
         with:
           node-version: "22.x"
           cache: npm
@@ -35,7 +35,7 @@ jobs:
       # Upload full coverage report as an artifact for inspection; summary
       # appears in the Actions job log via @vitest/coverage-v8.
       - name: Upload coverage artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v5
         if: always()
         with:
           name: coverage-report

.github/workflows/e2e-playwright.yml

@@ -20,9 +20,9 @@ jobs:
         browser: [chromium]
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v5
         with:
           node-version: "22.x"
           cache: npm
@@ -33,7 +33,7 @@ jobs:
       # Cache Playwright browser binaries keyed on Playwright version +
       # browser list; avoids re-downloading ~100 MB per run.
       - name: Cache Playwright browsers
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         id: pw-cache
         with:
           path: |
@@ -56,9 +56,9 @@ jobs:
     needs: e2e-fast
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
 
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v5
         with:
           node-version: "22.x"
           cache: npm
@@ -67,7 +67,7 @@ jobs:
         run: npm ci
 
       - name: Cache Playwright browsers
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         id: pw-cache
         with:
           path: ~/.cache/ms-playwright