chore: clean up github actions workflows

.github/workflows/dotnetformat.yml

@@ -1,31 +0,0 @@
-name: Format check on pull request
-
-on:
-  push:
-    paths:
-    - 'Myriad/**'
-    - 'PluralKit.API/**'
-    - 'PluralKit.Bot/**'
-    - 'PluralKit.Core/**'
-  pull_request:
-    paths:
-    - 'Myriad/**'
-    - 'PluralKit.API/**'
-    - 'PluralKit.Bot/**'
-    - 'PluralKit.Core/**'
-
-jobs:
-  dotnet-format:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout repo
-        uses: actions/checkout@v2
-
-      - name: Add dotnet-format problem matcher
-        uses: xt0rted/dotnet-format-problem-matcher@v1
-
-      - name: Restore dotnet tools
-        uses: xt0rted/dotnet-tool-restore@v1
-
-      - name: Run dotnet format
-        uses: PluralKit/dotnet-format@fix/net6