Move lint job from push.yml to separate check.yml workflow (#4013)

## Why

Doesn't need to run on a schedule and always applies to all files in the
repository. Can consider separating fmt and lint in a follow-up PR.

Author: pietern

.github/workflows/check.yml

@@ -0,0 +1,49 @@
+name: check
+
+on:
+  pull_request:
+    types: [opened, synchronize]
+  merge_group:
+    types: [checks_requested]
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+
+      - uses: actions/setup-go@44694675825211faa026b3c33043df3e48a5fa00 # v6.0.0
+        with:
+          go-version-file: go.mod
+          # Use different schema from regular job, to avoid overwriting the same key
+          cache-dependency-path: |
+            go.sum
+            .golangci.yaml
+
+      - name: Run go mod tidy
+        run: go mod tidy
+
+      - name: Fail if go.mod/go.sum changed
+        run: git diff --exit-code
+
+      - name: Run Go lint checks (does not include formatting checks)
+        run: go tool -modfile=tools/go.mod golangci-lint run --timeout=15m
+
+      - name: Run ruff (Python linter and formatter)
+        uses: astral-sh/ruff-action@57714a7c8a2e59f32539362ba31877a1957dded1 # v3.5.1
+        with:
+          version: "0.9.1"
+          args: "format --check"
+
+      - name: "make fmtfull: Python and Go formatting"
+        # Python formatting is already checked above, but this also checks Go and YAML formatting
+        # and verifies that the make command works correctly
+        run: |
+          make fmtfull
+          git diff --exit-code
+
+      - name: "make checks: custom checks outside of fmt and lint"
+        run: |-
+          make checks
+          git diff --exit-code

.github/workflows/push.yml

@@ -104,43 +104,6 @@ jobs:
       - name: Analyze slow tests
         run: make slowest
 
-  linters:
-    needs: cleanups
-    name: lint
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-      - uses: actions/setup-go@44694675825211faa026b3c33043df3e48a5fa00 # v6.0.0
-        with:
-          go-version-file: go.mod
-          # Use different schema from regular job, to avoid overwriting the same key
-          cache-dependency-path: |
-            go.sum
-            .golangci.yaml
-      - name: Run go mod tidy
-        run: |
-          go mod tidy
-      - name: Fail on differences
-        run: |
-          # Exit with status code 1 if there are differences (i.e. unformatted files)
-          git diff --exit-code
-      - name: Run Go lint checks (does not include formatting checks)
-        run: go tool -modfile=tools/go.mod golangci-lint run --timeout=15m
-      - name: Run ruff (Python linter and formatter)
-        uses: astral-sh/ruff-action@57714a7c8a2e59f32539362ba31877a1957dded1 # v3.5.1
-        with:
-          version: "0.9.1"
-          args: "format --check"
-      - name: "make fmtfull: Python and Go formatting"
-        # This is already done by actions, but good to check that make command is working
-        run: |
-          make fmtfull
-          git diff --exit-code
-      - name: "make checks: custom checks outside of fmt and lint"
-        run: |
-          make checks
-          git diff --exit-code
-
   validate-generated-is-up-to-date:
     needs: cleanups
     runs-on: ubuntu-latest