refactor: update module path to new repository location

Remove GitLab CI linter configuration and update module path from 
`gitlab.com/unboundsoftware/shiny/authz_client` to 
`git.unbound.se/shiny/authz_client` in all relevant files. 
These changes reflect a migration to a new hosting service.

.pre-commit-config.yaml

@@ -10,13 +10,6 @@ repos:
     args:
     - --allow-multiple-documents
   - id: check-added-large-files
-- repo: https://gitlab.com/devopshq/gitlab-ci-linter
-  rev: v1.0.6
-  hooks:
-  - id: gitlab-ci-linter
-    args:
-    - --project
-    - unboundsoftware/shiny/authz_client
 - repo: https://github.com/alessandrojcm/commitlint-pre-commit-hook
   rev: v9.23.0
   hooks:
@@ -30,7 +23,7 @@ repos:
   - id: go-imports
     args:
     - -local
-    - gitlab.com/unboundsoftware/shiny/authz_client
+    - git.unbound.se/shiny/authz_client
 - repo: https://github.com/lietu/go-pre-commit
   rev: v1.0.0
   hooks: