fix(bootstrap): use shared pip-based git install on Photon OS, fix Ubuntu 26.04 CI pip breakage

Photon's git installer called `setup.py install` directly, which fails
under modern setuptools ("egg-based install has been removed"). Route
it through the shared __install_salt_from_repo() helper like every
other distro's git installer.

Also add ubuntu-2604 to the --break-system-packages allowlist in
test-linux.yml, since its Python 3.14 enforces PEP 668 and the CI
dependency install step was failing before bootstrap-salt.sh even ran.

Author: twangboy

.github/workflows/test-linux.yml

@@ -64,12 +64,12 @@ jobs:
           /usr/bin/docker start ${{ github.run_id }}_salt-test
 
       - name: "Install Python Dependencies with pip breakage in container ${{ inputs.container-slug }}"
-        if: ${{ ( inputs.distro-slug == 'debian-12' ) || ( inputs.distro-slug == 'debian-13' ) || ( inputs.distro-slug == 'ubuntu-2404' ) }}
+        if: ${{ ( inputs.distro-slug == 'debian-12' ) || ( inputs.distro-slug == 'debian-13' ) || ( inputs.distro-slug == 'ubuntu-2404' ) || ( inputs.distro-slug == 'ubuntu-2604' ) }}
         run: |
           docker exec ${{ github.run_id}}_salt-test python3 -m pip install --break-system-packages -r /_w/btstrap/tests/requirements.txt
 
       - name: "Install Python Dependencies without pip breakage in container ${{ inputs.container-slug }}"
-        if: ${{ ( inputs.distro-slug != 'debian-12' ) && ( inputs.distro-slug != 'debian-13' ) && ( inputs.distro-slug != 'ubuntu-2404' ) }}
+        if: ${{ ( inputs.distro-slug != 'debian-12' ) && ( inputs.distro-slug != 'debian-13' ) && ( inputs.distro-slug != 'ubuntu-2404' ) && ( inputs.distro-slug != 'ubuntu-2604' ) }}
         run: |
           docker exec ${{ github.run_id}}_salt-test python3 -m pip install -r /_w/btstrap/tests/requirements.txt
 

bootstrap-salt.sh

@@ -6722,11 +6722,7 @@ install_vmware_photon_os_git() {
 
     install_vmware_photon_os_git_deps
 
-    if [ -f "${_SALT_GIT_CHECKOUT_DIR}/salt/syspaths.py" ]; then
-        ${_PYEXE} setup.py --salt-config-dir="$_SALT_ETC_DIR" --salt-cache-dir="${_SALT_CACHE_DIR}" ${SETUP_PY_INSTALL_ARGS} install --prefix=/usr || return 1
-    else
-        ${_PYEXE} setup.py ${SETUP_PY_INSTALL_ARGS} install --prefix=/usr || return 1
-    fi
+    __install_salt_from_repo "${_PYEXE}" || return 1
     return 0
 }