revert(ci): restore GitHub-hosted runners (#378)

## Summary
- revert the self-hosted runner migration
- restore GitHub-hosted workflow execution for this repo
- remove the netcup runner dependency from CI

#### Test plan
- [x] Confirmed the revert removes `self-hosted` from the workflow files

Author: barrettruth

.github/workflows/luarocks.yaml

@@ -11,7 +11,7 @@ jobs:
 
   publish:
     needs: ci
-    runs-on: [self-hosted, linux, x64, netcup, general]
+    runs-on: ubuntu-latest
 
     steps:
       - uses: actions/checkout@v4

.github/workflows/quality.yaml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   changes:
-    runs-on: [self-hosted, linux, x64, netcup, general]
+    runs-on: ubuntu-latest
     outputs:
       lua: ${{ steps.changes.outputs.lua }}
       python: ${{ steps.changes.outputs.python }}
@@ -44,7 +44,7 @@ jobs:
 
   lua-format:
     name: Lua Format Check
-    runs-on: [self-hosted, linux, x64, netcup, general]
+    runs-on: ubuntu-latest
     needs: changes
     if: ${{ needs.changes.outputs.lua == 'true' }}
     steps:
@@ -54,7 +54,7 @@ jobs:
 
   lua-lint:
     name: Lua Lint Check
-    runs-on: [self-hosted, linux, x64, netcup, general]
+    runs-on: ubuntu-latest
     needs: changes
     if: ${{ needs.changes.outputs.lua == 'true' }}
     steps:
@@ -64,7 +64,7 @@ jobs:
 
   lua-typecheck:
     name: Lua Type Check
-    runs-on: [self-hosted, linux, x64, netcup, general]
+    runs-on: ubuntu-latest
     needs: changes
     if: ${{ needs.changes.outputs.lua == 'true' }}
     steps:
@@ -78,7 +78,7 @@ jobs:
 
   python-format:
     name: Python Format Check
-    runs-on: [self-hosted, linux, x64, netcup, general]
+    runs-on: ubuntu-latest
     needs: changes
     if: ${{ needs.changes.outputs.python == 'true' }}
     steps:
@@ -92,7 +92,7 @@ jobs:
 
   python-lint:
     name: Python Lint Check
-    runs-on: [self-hosted, linux, x64, netcup, general]
+    runs-on: ubuntu-latest
     needs: changes
     if: ${{ needs.changes.outputs.python == 'true' }}
     steps:
@@ -106,7 +106,7 @@ jobs:
 
   python-typecheck:
     name: Python Type Check
-    runs-on: [self-hosted, linux, x64, netcup, general]
+    runs-on: ubuntu-latest
     needs: changes
     if: ${{ needs.changes.outputs.python == 'true' }}
     steps:
@@ -120,7 +120,7 @@ jobs:
 
   vimdoc-check:
     name: Vimdoc Check
-    runs-on: [self-hosted, linux, x64, netcup, general]
+    runs-on: ubuntu-latest
     needs: changes
     if: ${{ needs.changes.outputs.vimdoc == 'true' }}
     steps:
@@ -130,7 +130,7 @@ jobs:
 
   markdown-format:
     name: Markdown Format Check
-    runs-on: [self-hosted, linux, x64, netcup, general]
+    runs-on: ubuntu-latest
     needs: changes
     if: ${{ needs.changes.outputs.markdown == 'true' }}
     steps:

.github/workflows/test.yaml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   changes:
-    runs-on: [self-hosted, linux, x64, netcup, general]
+    runs-on: ubuntu-latest
     outputs:
       lua: ${{ steps.changes.outputs.lua }}
       python: ${{ steps.changes.outputs.python }}
@@ -37,7 +37,7 @@ jobs:
 
   python-test:
     name: Python Tests
-    runs-on: [self-hosted, linux, x64, netcup, general]
+    runs-on: ubuntu-latest
     needs: changes
     if: ${{ needs.changes.outputs.python == 'true' }}
     steps: