Automate release process via Changesets (#3915)

Co-authored-by: Francisco <fg@frang.io>

scripts/release/workflow/prepare-release-merge.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+# Define merge branch name
+MERGE_BRANCH=merge/$GITHUB_REF_NAME
+
+# Create the branch and force to start from ref
+git checkout -B "$MERGE_BRANCH" "$GITHUB_REF_NAME"
+
+# Get deleted changesets in this branch that might conflict with master
+readarray -t DELETED_CHANGESETS < <(git diff origin/master --name-only -- '.changeset/*.md')
+
+# Merge master, which will take those files cherry-picked. Auto-resolve conflicts favoring master.
+git merge origin/master -m "Merge master to $GITHUB_REF_NAME" -X theirs
+
+# Remove the originally deleted changesets to correctly sync with master
+rm -f "${DELETED_CHANGESETS[@]}"
+
+git add .changeset/
+
+# Allow empty here since there may be no changes if `rm -f` failed for all changesets
+git commit --allow-empty -m "Sync changesets with master"
+git push -f origin "$MERGE_BRANCH"