Merge branch 'code-suggestions/419679-remove-external-token-call' into 'master'

Self-generate JWT for SaaS completions

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/127863



Merged-by: Matthias Käppler <mkaeppler@gitlab.com>
Approved-by: Matthias Käppler <mkaeppler@gitlab.com>
Reviewed-by: Matthias Käppler <mkaeppler@gitlab.com>
Reviewed-by: Mikołaj Wawrzyniak <mwawrzyniak@gitlab.com>
Reviewed-by: Max Woolf <mwoolf@gitlab.com>
Co-authored-by: Max Woolf <mwoolf@gitlab.com>