ci: Ignore v1 updates for checkout (#5023)

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

.github/dependabot.yml

@@ -9,3 +9,7 @@ updates:
       actions:
         patterns:
           - "*"
+    ignore:
+      - dependency-name: actions/checkout
+        versions:
+          - "<2"

.github/workflows/ci.yml

@@ -529,8 +529,6 @@ jobs:
   # Testing on ICC using the oneAPI apt repo
   icc:
     runs-on: ubuntu-20.04
-    strategy:
-      fail-fast: false
 
     name: "🐍 3 • ICC latest • x64"
 

.pre-commit-config.yaml

@@ -146,3 +146,10 @@ repos:
   hooks:
   - id: pylint
     files: ^pybind11
+
+- repo: https://github.com/python-jsonschema/check-jsonschema
+  rev: 0.28.0
+  hooks:
+  - id: check-readthedocs
+  - id: check-github-workflows
+  - id: check-dependabot