Fix generate_versions job (#1752)

Since #1742, the `generate_versions` CI job [succeeds even though it
can't parse the JSON file][1]. Parsing fails because `jq` [doesn't
support JSON5][2]. The job succeeds silently despite this failure
because it's ran inside [command substitution][3]. This currently
results in #1751 not running proper tests.

Fix the `generate_versions` CI job to correctly parse the JSON5 file by
stripping comment lines before passing its content to `jq`. Also ensure
the job will fail if the step fails by running it once outside command
substitution and ensuring `pipefail` is on. This replaces the "debug"
step.

[1]:
https://github.com/gradle/android-cache-fix-gradle-plugin/actions/runs/12717112831
[2]: jqlang/jq#1571
[3]:
https://www.gnu.org/software/bash/manual/html_node/Command-Substitution.html

.github/workflows/build-verification.yml

@@ -13,9 +13,15 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - id: setup-matrix
-        run: echo "matrix=$(jq -cM '.supportedVersions | keys' src/main/resources/versions.json | sed -e 's/\./_/g' -e 's/-/_/g')" >> $GITHUB_OUTPUT
-      - name: debug
-        run: echo "matrix=${{ steps.setup-matrix.outputs.matrix }}"
+        shell: bash
+        run: |
+          set -euo pipefail
+          json_to_matrix() {
+            json_without_comments="$(sed -E 's|\s//.*||' src/main/resources/versions.json5)"
+            echo "$json_without_comments" | jq -cM '.supportedVersions | keys' | sed -e 's/\./_/g' -e 's/-/_/g'
+          }
+          json_to_matrix
+          echo "matrix=$(json_to_matrix)" >> $GITHUB_OUTPUT
     outputs:
       matrix: ${{ steps.setup-matrix.outputs.matrix }}