Remove unneeded files

I don't actually need any formal bug report or merge request templates filled in, so getting ride of those meta files.

.github/workflows/core-build.yml

@@ -1,12 +0,0 @@
-name: core-build
-on:
-  push:
-    branches:
-      - 'master'
-  pull_request:
-
-jobs:
-  build:
-    uses: azerothcore/reusable-workflows/.github/workflows/core_build_modules.yml@main
-    with:
-      module_repo: ${{ github.event.repository.name }}