v1.15.11

* SECURITY
  * Only view milestones from current repo (#18414) (#18418)
* BUGFIXES
  * Fix broken when no commits and default branch is not master (#18422) (#18424)
  * Fix commit's time (#18375) (#18409)
  * Fix restore without topic failure (#18387) (#18401)
  * Fix mermaid import in 1.15 (it uses ESModule now) (#18382)
  * Update to go/text 0.3.7 (#18336)
* MISC
  * Upgrade EasyMDE to 2.16.1 (#18278) (#18279)