github-workflow: don't run slotscheck (not installed)

.github/workflows/validation.yml

@@ -33,7 +33,7 @@ jobs:
           restore-keys: "precommit-${{ runner.os }}-${{ steps.poetry_setup.outputs-python-version}}-"
 
       - name: Run pre-commit hooks
-        run: SKIP=ruff-linter,ruff-formatter,slotscheck,basedpyright pre-commit run --all-files
+        run: SKIP=ruff-linter,ruff-formatter,basedpyright pre-commit run --all-files
 
       - name: Run ruff linter
         run: ruff check --output-format=github --show-fixes --exit-non-zero-on-fix .
@@ -41,8 +41,5 @@ jobs:
       - name: Run ruff formatter
         run: ruff format --diff .
 
-      - name: Run slotscheck
-        run: slotscheck -m mcproto
-
       - name: Run basedpyright type checker
         run: basedpyright --warnings .