chore: remove centralizable repo config

- Remove .github conf folder from Flarum packages

- Remove styleci config from all packages

extensions/flags/.github/workflows/backend.yml

@@ -1,15 +0,0 @@
-name: Flags PHP
-
-on: [workflow_dispatch, push, pull_request]
-
-# The reusable workflow definitions will be moved to the `flarum/framework` repo soon.
-# This will break your current script.
-# When this happens, run `flarum-cli audit infra --fix` to update your infrastructure.
-
-jobs:
-  run:
-    uses: flarum/.github/.github/workflows/REUSABLE_backend.yml@main
-    with:
-      enable_backend_testing: true
-
-      backend_directory: .

extensions/flags/.github/workflows/frontend.yml

@@ -1,21 +0,0 @@
-name: Flags JS
-
-on: [workflow_dispatch, push, pull_request]
-
-# The reusable workflow definitions will be moved to the `flarum/framework` repo soon.
-# This will break your current script.
-# When this happens, run `flarum-cli audit infra --fix` to update your infrastructure.
-
-jobs:
-  run:
-    uses: flarum/.github/.github/workflows/REUSABLE_frontend.yml@main
-    with:
-      enable_bundlewatch: false
-      enable_prettier: true
-      enable_typescript: true
-
-      frontend_directory: ./js
-      main_git_branch: master
-
-    secrets:
-      bundlewatch_github_token: ${{ secrets.BUNDLEWATCH_GITHUB_TOKEN }}

extensions/flags/.styleci.yml

@@ -1,14 +0,0 @@
-preset: recommended
-
-enabled:
-  - logical_not_operators_with_successor_space
-
-disabled:
-  - align_double_arrow
-  - blank_line_after_opening_tag
-  - multiline_array_trailing_comma
-  - new_with_braces
-  - phpdoc_align
-  - phpdoc_order
-  - phpdoc_separation
-  - phpdoc_types