feat: rebase stale pin branches (#1099)

lib/config/definitions.js

@@ -404,6 +404,7 @@ const options = [
     default: {
       unpublishSafe: false,
       recreateClosed: true,
+      rebaseStalePrs: true,
       groupName: 'Pin Dependencies',
       group: {
         commitMessage: 'Pin Dependencies',

test/workers/package/__snapshots__/index.spec.js.snap

@@ -148,7 +148,7 @@ This {{#if isGitHub}}PR{{else}}MR{{/if}} has been generated by [Renovate Bot](ht
   "prCreation": "immediate",
   "prNotPendingHours": 12,
   "prTitle": "{{#if isPin}}Pin{{else}}{{#if isRollback}}Roll back{{else}}Update{{/if}}{{/if}} dependency {{depName}} to {{#if isRange}}{{newVersion}}{{else}}{{#if isMajor}}v{{newVersionMajor}}{{else}}v{{newVersion}}{{/if}}{{/if}}",
-  "rebaseStalePrs": false,
+  "rebaseStalePrs": true,
   "recreateClosed": true,
   "requiredStatusChecks": Array [],
   "reviewers": Array [],