Fix generated docs_config.js on CI (#12618)

Author: ericmj

.github/workflows/builds.hex.pm.yml

@@ -35,6 +35,8 @@ jobs:
       - uses: actions/checkout@v3
         with:
           fetch-depth: 50
+      - name: Get tags
+        run: git fetch --tags origin
       - uses: ./.github/workflows/release_pre_built
         with:
           otp_version: ${{ matrix.otp_version }}