diff --git a/.github/workflows/run-dep-tests.yml b/.github/workflows/run-dep-tests.yml
index 445139467b81..8eb4cd0b5580 100644
--- a/.github/workflows/run-dep-tests.yml
+++ b/.github/workflows/run-dep-tests.yml
@@ -19,9 +19,9 @@ jobs:
         os: [ubuntu-latest, macOS-latest, windows-latest]
 
     steps:
-    - uses: actions/checkout@8ade135a41bc03ea155e62e844d188df1ea18608
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@0a5c61591373683505ea898e09a3ea4f39ef2b9c
+      uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install dependencies
diff --git a/.github/workflows/run-tests.yml b/.github/workflows/run-tests.yml
index e883041e4935..27c05a9d9110 100644
--- a/.github/workflows/run-tests.yml
+++ b/.github/workflows/run-tests.yml
@@ -20,9 +20,9 @@ jobs:
         os: [ubuntu-latest, macOS-latest, windows-latest]
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install dependencies
diff --git a/.github/workflows/source-dist-tests.yml b/.github/workflows/source-dist-tests.yml
index 6f8784caf948..3b6d39117caa 100644
--- a/.github/workflows/source-dist-tests.yml
+++ b/.github/workflows/source-dist-tests.yml
@@ -19,9 +19,9 @@ jobs:
         python-version: ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14"]
         os: [ubuntu-latest, macOS-latest, windows-latest]
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install dependencies
diff --git a/.github/workflows/update-lockfiles.yml b/.github/workflows/update-lockfiles.yml
index bac84867b0b6..3b2cdc12491e 100644
--- a/.github/workflows/update-lockfiles.yml
+++ b/.github/workflows/update-lockfiles.yml
@@ -34,11 +34,11 @@ jobs:
         os: [macOS-latest, windows-latest]
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
         with:
           ref: ${{ github.event.inputs.ref }}
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405
         with:
           python-version: ${{ matrix.python-version }}
 
diff --git a/scripts/ci/run-tests b/scripts/ci/run-tests
index 4c4676f586c3..4afb287f8878 100755
--- a/scripts/ci/run-tests
+++ b/scripts/ci/run-tests
@@ -52,7 +52,17 @@ def process_args(args):
         test_args += f'--junit-xml={args.junit_xml_path} '
     if args.markers:
         test_args += f'-m {args.markers} '
-    test_args += '--numprocesses=auto --dist=loadfile --maxprocesses=4 '
+    if os.getenv('PYTEST_XDIST_AUTO_NUM_WORKERS'):
+        # If the user set PYTEST_XDIST_AUTO_NUM_WORKERS,
+        # use that to limit max processes
+        max_processes = int(os.environ['PYTEST_XDIST_AUTO_NUM_WORKERS'])
+    elif os.getenv('GITHUB_ACTIONS', 'false') == 'true':
+        # Limiting parallelism in GitHub, to avoid the
+        # 'Error: The operation was canceled.' issues in 2026
+        max_processes=3
+    else:
+        max_processes=4
+    test_args += f'--numprocesses=auto --dist=loadfile --maxprocesses={max_processes} '
     dirs = " ".join(args.test_dirs)
 
     return runner, test_args, dirs