chore: add labels and pass release branch variable

Author: hoolioh

.github/workflows/release-proposal-dispatch.yml

@@ -462,6 +462,8 @@ jobs:
             --title "chore(release): proposal for ${{ inputs.crate }}" \
             --body "$PR_BODY" \
             --label "release-proposal" \
+            --label "skip-metadata-check" \
+            --label "skip-changelog-check" \
             --base "${{ needs.cargo-release.outputs.ephemeral_branch }}"
 
       - name: Cleanup on failure

.gitlab-ci.yml

@@ -20,7 +20,12 @@ trigger_internal_build:
     LIBDATADOG_COMMIT_BEFORE_SHA: $CI_COMMIT_BEFORE_SHA
     LIBDATADOG_COMMIT_TITLE: $CI_COMMIT_TITLE
     LIBDATADOG_ENABLE_MACOS_JOBS: "false"
+    LIBDATADOG_IS_RELEASE_BRANCH: "false"
   rules:
+    - if: '$CI_COMMIT_BRANCH =~ /^release\//'
+      variables:
+        LIBDATADOG_IS_RELEASE_BRANCH: "true"
+      when: always
     - if: '$CI_MERGE_REQUEST_LABELS =~ /run-macos-tests/'
       variables:
         LIBDATADOG_ENABLE_MACOS_JOBS: "true"