[CI] Add criticality of release to release notes (#1259)

* Enforces presence of C-labels to designate the importance of a release
* Iterates over them on a release, takes the highest present and includes it in the release notes
* Lists the change(s) that caused the release to be that priority

polkadot/.gitlab-ci.yml

@@ -157,9 +157,7 @@ build-wasm-release:
   <<:                             *compiler_info
   # Note: We likely only want to do this for tagged releases, hence the 'only:'
   only:
-    # FIXME remove when ready to merge
-    - /^[0-9]+$/
-    # - /^v[0-9]+\.[0-9]+.*$/        # i.e. v1.0, v2.1rc1
+    - /^v[0-9]+\.[0-9]+.*$/        # i.e. v1.0, v2.1rc1
   script:
     - time wasm-pack build --target web --out-dir wasm --release cli -- --no-default-features --features browser
     - mkdir -p ./artifacts/wasm