Opitmize migration process by using both unmanaged_kubernetes_service and kubernetes_service_without_template

Merge branch '39957-redirect-to-gpc-page-if-users-try-to-create-a-cluster-but-the-account-is-not-enabled' into 'master'

Resolve "Redirect to GCP page if users try to create a cluster but the account is not enabled"

Closes #39957 and #41410

See merge request gitlab-org/gitlab-ce!15665

Fix restoring associations with import/export

Closes #41646

See merge request gitlab-org/gitlab-ce!16221

10.4 licenses update

Closes #10

See merge request gitlab-org/gitlab-ce!16269

10.4 templates update

Closes #10

See merge request gitlab-org/gitlab-ce!16266

Fix error 500 when viewing commit and merge request diffs

Closes #41735

See merge request gitlab-org/gitlab-ce!16272

Due to the refactoring in !16082, `Blob#batch` no longer falls back
to a default `blob_size_limit`. Since `Repository#batch_blobs` was using
a default `nil` value, this would cause issues in the `Blob#find_by_rugged`
method.

This fix here is to be consistent and use a non-nil default value in
`Repository#batch_blobs`.

The problem was masked in development and tests because Gitaly is always
enabled by default for all features.

Closes #41735

Merge branch 'master' into 39957-redirect-to-gpc-page-if-users-try-to-create-a-cluster-but-the-account-is-not-enabled

Resolve "Improve non-triggered manual action job detail page"

Closes #22643 and #37843

See merge request gitlab-org/gitlab-ce!15991