ci: Fix snap promote to correct channel

.github/workflows/release.yaml

@@ -182,8 +182,7 @@ jobs:
         env: # Workaround for https://github.com/snapcore/snapcraft/issues/4439
           SNAPCRAFT_HAS_TTY: "true"
         run: |
-          RELEASE_TYPE=$(echo "${{ github.ref }}" | awk -F"/" '{print $3}')
+          if [[ $GITHUB_REF_NAME == rc* ]]; then
-          if [ "$RELEASE_TYPE" = "rc" ]; then
               yes | snapcraft promote fluffychat --from-channel edge --to-channel candidate
           else
               yes | snapcraft promote fluffychat --from-channel edge --to-channel stable