ci: Use default architecture for all runners (#58)

Author: sethaxen

.github/workflows/ci.yml

@@ -24,7 +24,6 @@ jobs:
       - uses: julia-actions/setup-julia@v2
         with:
           version: ${{ matrix.julia-version }}
-          arch: x64
       - uses: julia-actions/cache@v2
       - name: Cache CondaPkg
         id: cache-condaPkg