[ci] Don't check matrix.os when runner.os suffices (#8863)

There's no real need to manually check the `runs-on`, as `runner.os`
provides a universally identifiable string for checking this anyways.

Signed-off-by: crueter <crueter@eden-emu.dev>

.github/workflows/bazel.yml

@@ -39,6 +39,7 @@ jobs:
         run: df -h
 
       - name: Free disk space (Linux)
+        if: runner.os == 'Linux'
         uses: jlumbroso/free-disk-space@main
         with:
           tool-cache: false
@@ -48,8 +49,9 @@ jobs:
           large-packages: false
           docker-images: false
           swap-storage: false
-        if: startsWith(matrix.os, 'ubuntu')
+
       - name: Free disk space (macOS)
+        if: runner.os == 'macOS'
         # CodeQL: 5G
         # go: 748M
         # Android: 12G
@@ -57,7 +59,6 @@ jobs:
           rm -rf /Users/runner/hostedtoolcache/CodeQL
           rm -rf /Users/runner/hostedtoolcache/go
           rm -rf /Users/runner/Library/Android
-        if: startsWith(matrix.os, 'macOS')
 
       - name: Check disk free space post-cleanup
         run: df -h
@@ -72,10 +73,10 @@ jobs:
           password: ${{ secrets.BAZEL_CACHE_PASSWORD }}
 
       - name: Install apt dependencies
-        if: matrix.os == 'ubuntu-24.04'
+        if: runner.os == 'Linux'
         run: sudo apt-get update && sudo apt-get install -y libgl1-mesa-dev libx11-dev libxcursor-dev libxi-dev libxinerama-dev libxrandr-dev avahi-daemon
 
-      - if: matrix.os == 'ubuntu-24.04'
+      - if: runner.os == 'Linux'
         uses: bazel-contrib/setup-bazel@0.15.0
         with:
           bazelisk-cache: true
@@ -85,12 +86,12 @@ jobs:
       - name: bazel ${{ matrix.action }}
         run: |
           ACTION='${{ matrix.action }}'
-          if [[ "${ACTION}" == "build" ]]; then
+          if [ "${ACTION}" = "build" ]; then
             TARGETS=:publish
           else
             TARGETS=...
           fi
-          if [[ "${{ matrix.os }}" == "windows-2022" ]]; then
+          if [ "${{ runner.os }}" = "Windows" ]; then
             bazel --output_user_root=C:\\bazelroot ${ACTION} ${TARGETS} --config=ci -c opt --repo_env=WPI_PUBLISH_CLASSIFIER_FILTER='${{ matrix.classifier }}'
           else
             bazel ${ACTION} ${TARGETS} --config=ci -c opt --repo_env=WPI_PUBLISH_CLASSIFIER_FILTER='${{ matrix.classifier }}'