chore: remove leading and trailing whitespace from extracted release notes

Author: agarvin-nr

.github/workflows/release-draft.yaml

@@ -72,11 +72,16 @@ jobs:
       - name: Extract release notes
         run: |
           release_notes_file="${RUNNER_TEMP}/release-notes.md"
-          awk '/<!-- next version -->/{inside=1;next} /<!-- previous-version -->/{exit} inside' \
-            CHANGELOG.md > "$release_notes_file"
+
+          # Grab changelog from between version markers, then remove leading / trailing whitespace and print to temp file.
+          awk 'inside && /<!-- previous-version -->/{exit} inside{print} /<!-- next version -->/{inside=1}' CHANGELOG.md \
+          | awk 'NF{content=1} content{buf=buf $0 ORS} END{sub(/\n+$/,"\n",buf); printf "%s",buf}' > "$release_notes_file"
+
           if [ ! -s "$release_notes_file" ]; then
-            echo "_No user-facing changes._" > "$release_notes_file"
+              echo "Error: no user-facing changes found between version markers in CHANGELOG.md; aborting release." >&2
+              exit 1
           fi
+
           echo "release_notes_file=$release_notes_file" >> "$GITHUB_ENV"
           echo "Release notes:"
           cat "$release_notes_file"