Bump actions/checkout from 2.3.5 to 2.4.0

Bumps [actions/checkout](https://github.com/actions/checkout) from 2.3.5 to 2.4.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v2.3.5...v2.4.0)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/maven.yml

@@ -40,7 +40,7 @@ jobs:
       fail-fast: false
 
     steps:
-    - uses: actions/checkout@v2.3.5
+    - uses: actions/checkout@v2.4.0
     - uses: actions/cache@v2.1.6
       with:
         path: ~/.m2/repository

src/changes/changes.xml

@@ -304,7 +304,7 @@ The <action> type attribute can be add,update,fix,remove.
         Bump jmh.version from 1.32 to 1.33 #258.
       </action>
       <action dev="ggregory" type="update" due-to="Dependabot">
-        Bump actions/checkout from 2.3.4 to 2.3.5 #286.
+        Bump actions/checkout from 2.3.4 to 2.4.0 #286, #298.
       </action>
       <action dev="kinow" type="update" due-to="Dependabot">
         Bump moditect-maven-plugin from 1.0.0.RC1 to 1.0.0.RC2 #280.