fix: run validation pipelines using latest clas12Tags semver tag (#170

)

* fix: run validation pipelines using latest `clas12Tags` semver tag

* fix: escape backtick

.github/workflows/validation.yml

@@ -12,10 +12,42 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
+
+  get_gemc_tag:
+    runs-on: ubuntu-latest
+    name: Get highest GEMC tag
+    outputs:
+      tag: ${{ steps.tag.outputs.tag }}
+    steps:
+      - name: checkout clas12-validation
+        uses: actions/checkout@v4
+        with:
+          repository: JeffersonLab/clas12-validation
+          ref: main
+          path: clas12-validation
+      - name: checkout clas12Tags
+        uses: actions/checkout@v4
+        with:
+          repository: gemc/clas12Tags
+          ref: main
+          clean: false
+          fetch-tags: true
+          fetch-depth: 0
+          path: clas12Tags
+      - name: get highest tag
+        id: tag
+        working-directory: clas12Tags
+        run: |
+          tag=$(../clas12-validation/bin/get_highest_tag.rb)
+          echo "Highest \`clas12Tags\` (GEMC) tag: \`$tag\`" >> $GITHUB_STEP_SUMMARY
+          echo '- using this version for `clas12-validation` workflow run' >> $GITHUB_STEP_SUMMARY
+          echo tag=$tag >> $GITHUB_OUTPUT
+
   validation:
+    needs: [ get_gemc_tag ]
     uses: JeffersonLab/clas12-validation/.github/workflows/ci.yml@main
     with:
       git_upstream: >-
         {
-          "clas12Tags": { "fork": "gemc/clas12Tags", "branch": "8f9956678b44386d3df85d8d8df9d5002333a82b" }
+          "clas12Tags": { "fork": "gemc/clas12Tags", "branch": "${{ needs.get_gemc_tag.outputs.tag }}" }
         }