tools: improve release proposal PR opening

- Open as draft. The releaser should review the PR and mark it as ready.
- Add the "release" label.
- Assign the releaser to the PR so it's clearer who's in charge and
  they can find it more easily. This will also notify and subscribe
  them to the PR.

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

@@ -32,6 +32,7 @@ jobs:
       RELEASE_BRANCH: v${{ inputs.release-line }}.x
       RELEASE_DATE: ${{ inputs.release-date }}
       RELEASE_LINE: ${{ inputs.release-line }}
+      RELEASER: ${{ github.actor }}
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683  # v4.2.2
@@ -78,7 +79,7 @@ jobs:
         run: |
           git update-index --assume-unchanged tools/actions/create-release.sh
           curl -fsSLo tools/actions/create-release.sh https://github.com/${GITHUB_REPOSITORY}/raw/${GITHUB_SHA}/tools/actions/create-release.sh
-          ./tools/actions/create-release.sh "${RELEASE_DATE}" "${RELEASE_LINE}"
+          ./tools/actions/create-release.sh "${RELEASE_DATE}" "${RELEASE_LINE}" "${RELEASER}"
         env:
           GH_TOKEN: ${{ github.token }}
           # We want the bot to push the push the release commit so CI runs on it.

tools/actions/create-release.sh

@@ -7,6 +7,7 @@ BOT_TOKEN=${BOT_TOKEN:-}
 
 RELEASE_DATE=$1
 RELEASE_LINE=$2
+RELEASER=$3
 
 if [ -z "$RELEASE_DATE" ] || [ -z "$RELEASE_LINE" ]; then
   echo "Usage: $0 <RELEASE_DATE> <RELEASE_LINE>"
@@ -48,7 +49,7 @@ PR_URL="$(gh api \
   -H "Accept: application/vnd.github+json" \
   -H "X-GitHub-Api-Version: 2022-11-28" \
   "/repos/${GITHUB_REPOSITORY}/pulls" \
-   -f "title=$TITLE" -f "body=$TEMP_BODY" -f "head=$HEAD_BRANCH" -f "base=v$RELEASE_LINE.x")"
+   -f "title=$TITLE" -f "body=$TEMP_BODY" -f "head=$HEAD_BRANCH" -f "base=v$RELEASE_LINE.x" -f draft=true)"
 
 # Push the release commit to the proposal branch using `BOT_TOKEN` from the env
 node --input-type=module - \
@@ -124,3 +125,5 @@ if (data.errors?.length) {
 }
 console.log(util.inspect(data, { depth: Infinity }));
 EOF
+
+gh pr edit "$PR_URL" --add-label release --add-assignee "$RELEASER"