fix(platform/github): don't retry merge when blocked by required status check

lib/modules/platform/github/index.spec.ts

@@ -2815,6 +2815,27 @@ describe('modules/platform/github/index', () => {
         })
       ).toBeFalse();
     });
+
+    it('should handle merge block', async () => {
+      const scope = httpMock.scope(githubApiHost);
+      initRepoMock(scope, 'some/repo');
+      scope
+        .put('/repos/some/repo/pulls/1234/merge')
+        .reply(405, { message: 'Required status check "build" is expected.' });
+      await github.initRepo({ repository: 'some/repo' });
+      const pr = {
+        number: 1234,
+        head: {
+          ref: 'someref',
+        },
+      };
+      expect(
+        await github.mergePr({
+          branchName: '',
+          id: pr.number,
+        })
+      ).toBeFalse();
+    });
   });
 
   describe('massageMarkdown(input)', () => {

lib/modules/platform/github/index.ts

@@ -32,6 +32,8 @@ import type {
 } from '../../../util/git/types';
 import * as hostRules from '../../../util/host-rules';
 import * as githubHttp from '../../../util/http/github';
+import type { GithubHttpOptions } from '../../../util/http/github';
+import type { HttpResponse } from '../../../util/http/types';
 import { regEx } from '../../../util/regex';
 import { sanitize } from '../../../util/sanitize';
 import { fromBase64, looseEquals } from '../../../util/string';
@@ -1605,15 +1607,15 @@ export async function mergePr({
   const url = `repos/${
     config.parentRepo ?? config.repository
   }/pulls/${prNo}/merge`;
-  const options: any = {
-    body: {} as { merge_method?: string },
+  const options: GithubHttpOptions = {
+    body: {},
   };
   // istanbul ignore if
   if (config.forkToken) {
     options.token = config.forkToken;
   }
   let automerged = false;
-  let automergeResult: any;
+  let automergeResult: HttpResponse<unknown>;
   if (config.mergeMethod) {
     // This path is taken if we have auto-detected the allowed merge types from the repo
     options.body.merge_method = config.mergeMethod;
@@ -1623,9 +1625,19 @@ export async function mergePr({
       automerged = true;
     } catch (err) {
       if (err.statusCode === 404 || err.statusCode === 405) {
-        // istanbul ignore next
+        const body = err.response?.body;
+        if (
+          body?.message &&
+          /^Required status check ".+" is expected\.$/.test(body.message)
+        ) {
+          logger.warn(
+            { response: body },
+            `GitHub blocking PR merge -- Missing required status check(s)`
+          );
+          return false;
+        }
         logger.debug(
-          { response: err.response ? err.response.body : undefined },
+          { response: body },
           'GitHub blocking PR merge -- will keep trying'
         );
       } else {
@@ -1661,7 +1673,7 @@ export async function mergePr({
     }
   }
   logger.debug(
-    { automergeResult: automergeResult.body, pr: prNo },
+    { automergeResult: automergeResult!.body, pr: prNo },
     'PR merged'
   );
   const cachedPr = config.prList?.find(({ number }) => number === prNo);