chore: backport changes to v3 with v3-backport branch prefix and label (#9283)

Author: edmundhung

tools/deployments/open-v3-pr.ts

@@ -6,10 +6,10 @@ import parseChangeset from "@changesets/parse";
 if (require.main === module) {
 	if (isWranglerPatch(process.env.FILES as string)) {
 		// Create a new branch for the v3 maintenance PR
-		execSync(`git checkout -b v3-maintenance-${process.env.PR_NUMBER} -f`);
+		execSync(`git checkout -b v3-backport-${process.env.PR_NUMBER} -f`);
 
 		execSync(
-			`git rebase --onto origin/v3-maintenance origin/main v3-maintenance-${process.env.PR_NUMBER}`
+			`git rebase --onto origin/v3-maintenance origin/main v3-backport-${process.env.PR_NUMBER}`
 		);
 
 		execSync(`git push origin HEAD --force`);
@@ -26,6 +26,7 @@ if (require.main === module) {
 					`--head v3-maintenance-${process.env.PR_NUMBER}`,
 					`--label "skip-pr-description-validation"`,
 					`--label "skip-v3-pr"`,
+					`--label "v3-backport"`,
 					`--title "V3 Backport [#${process.env.PR_NUMBER}]: ${process.env.PR_TITLE?.slice(1, -1)}"`,
 					`--body "This is an automatically opened PR to backport patch changes from #${process.env.PR_NUMBER} to Wrangler v3"`,
 					`--draft`,