Merge branch '59208-fix-error-500-on-every-page-when-active-broadcast-message-present-after-upgrading-to-11-9-0' into 'master'

Gracefully handles excluded fields from attributes during serialization on JsonCache

Closes #59208

See merge request gitlab-org/gitlab-ce!26368

(cherry picked from commit cc5095ed)

7028b376 Gracefully handles excluded fields from attributes during serialization
1c7a2c05 Add CHANGELOG entry