Merge branch '59-issue-template-for-master-broken' into 'master'

Create issue templates for master broken triage

See merge request gitlab-org/gitlab!90550

.gitlab/issue_templates/Broken Master - Flaky.md

+<!---
+This issue template is for a master pipeline is failing for a flaky reason that cannot be reliably reproduced.
+
+Please read the below documentations for a workflow of triaging and resolving broken master.
+
+- https://about.gitlab.com/handbook/engineering/workflow/#triage-broken-master
+- https://gitlab.com/gitlab-org/quality/engineering-productivity/team/-/blob/main/runbooks/master-broken.md
+- https://gitlab.com/gitlab-org/gitlab/-/blob/master/doc/development/testing_guide/flaky_tests.md
+--->
+
+### Summary
+
+<!-- Link to the failing master build and add the build failure output in the below code block section. -->
+
+### Steps to reproduce
+
+<!-- If the pipeline failure is reproducible, provide steps to recreate the issue locally. Please use an ordered list. -->
+
+### Proposed Resolution
+
+<!-- Describe the proposed change to restore master stability. -->
+
+Please refer to the [Resolution guidance](https://about.gitlab.com/handbook/engineering/workflow/#resolution-of-broken-master) to learn more about resolution of broken master.
+
+/label ~"failure::flaky-test" ~"Engineering Productivity" ~"priority::2" ~"severity::2"

.gitlab/issue_templates/Broken Master - Non-flaky.md

+<!---
+This issue template is for a master pipeline is failing for a non-flaky reason.
+
+Please read the below documentations for a workflow of triaging and resolving broken master.
+
+- https://about.gitlab.com/handbook/engineering/workflow/#triage-broken-master
+- https://gitlab.com/gitlab-org/quality/engineering-productivity/team/-/blob/main/runbooks/master-broken.md
+--->
+
+### Summary
+
+<!-- Link to the failing master build and add the build failure output in the below code block section. -->
+
+### Steps to reproduce
+
+<!-- If the pipeline failure is reproducible, provide steps to recreate the issue locally. Please use an ordered list. -->
+
+### Proposed Resolution
+
+<!-- Describe the proposed change to restore master stability. -->
+
+Please refer to the [Resolution guidance](https://about.gitlab.com/handbook/engineering/workflow/#resolution-of-broken-master) to learn more about resolution of broken master.
+
+/label ~"master:broken" ~"Engineering Productivity" ~"priority::1" ~"severity::1"