Fix repeated words throughout docs

doc/.vale/gitlab/Repetition.yml

doc/administration/auth/ldap-ee.md

doc/administration/auth/ldap-troubleshooting.md

doc/administration/auth/ldap.md

doc/administration/merge_request_diffs.md

doc/administration/scaling/index.md

doc/administration/troubleshooting/postgresql.md

doc/administration/troubleshooting/ssl.md

doc/api/deploy_tokens.md

doc/api/discussions.md

doc/api/epic_links.md

doc/api/releases/links.md

doc/api/runners.md

doc/ci/examples/laravel_with_gitlab_and_envoy/index.md

doc/ci/examples/test_phoenix_app_with_gitlab_ci_cd/index.md

doc/ci/pipelines/index.md

doc/ci/variables/README.md

doc/ci/yaml/README.md

doc/development/api_graphql_styleguide.md

doc/development/documentation/workflow.md