Remove trigram indexes for "ci_runners"

These indexes are only used when you search for runners in the admin
interface. This operation is so rarely used that it does not make sense
to slow down every update in order to update the GIN trigram indexes.

Removing these indexes should speed up queries such as those used for
updating the last contact time of CI runners. Locally the timings of
this query were reduced from ~50 ms to ~25 ms:

    UPDATE ci_runners SET updated_at = now(), contacted_at = now();

1 files changed, 1 insertions, 0 deletions

diff --git a/CHANGELOG b/CHANGELOG
index 42d32e53685..a317b69941b 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -36,6 +36,7 @@ v 8.11.0 (unreleased)
   - Retrieve rendered HTML from cache in one request
   - Fix renaming repository when name contains invalid chararacters under project settings
   - Upgrade Grape from 0.13.0 to 0.15.0. !4601
+  - Trigram indexes for the "ci_runners" table have been removed to speed up UPDATE queries
   - Fix devise deprecation warnings.
   - Update version_sorter and use new interface for faster tag sorting
   - Optimize checking if a user has read access to a list of issues !5370