ci: update V1_LATEST_TAG repo variable on stable releases

After creating a stable (non-prerelease) release, update the
V1_LATEST_TAG repo variable so the hermes v2 release workflow
can restore 'latest' to the correct v1 tag.

Author: kjiang-ac

.github/workflows/bun-compile.yml

@@ -159,3 +159,13 @@ jobs:
             $PRERELEASE_FLAG \
             artifacts/*
 
+      - name: Update V1_LATEST_TAG variable
+        if: ${{ !contains(inputs.version || github.event.client_payload.version, 'prerelease') }}
+        env:
+          GH_TOKEN: ${{ github.token }}
+          VERSION: ${{ inputs.version || github.event.client_payload.version }}
+        run: |
+          gh api --method PATCH "repos/${{ github.repository }}/actions/variables/V1_LATEST_TAG" \
+            -f name="V1_LATEST_TAG" \
+            -f value="v${VERSION}"
+