gha: release: only push images for tags and main branch (#1520)

Signed-off-by: Joe Lanford <joe.lanford@gmail.com>

Author: joelanford

.github/workflows/release.yaml

@@ -42,8 +42,8 @@ jobs:
           echo IMAGE_TAG="${GITHUB_REF#refs/tags/}" >> $GITHUB_ENV
           echo GORELEASER_ARGS="--clean" >> $GITHUB_ENV
           echo ENABLE_RELEASE_PIPELINE=true >> $GITHUB_ENV
-        elif [[ $GITHUB_REF == refs/heads/* ]]; then
-          # Branch build.
+        elif [[ $GITHUB_REF == refs/heads/main ]]; then
+          # 'main' branch build.
           echo IMAGE_TAG="$(echo "${GITHUB_REF#refs/heads/}" | sed -r 's|/+|-|g')" >> $GITHUB_ENV
           echo GORELEASER_ARGS="--clean --skip=validate" >> $GITHUB_ENV
         elif [[ $GITHUB_REF == refs/pull/* ]]; then