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](https://github.com/actions/checkout/compare/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>

.github/workflows/maven.yml

@@ -31,7 +31,7 @@ jobs:
 #            experimental: true
         
     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

@@ -242,7 +242,7 @@
       Update tests from commons-io:commons-io 2.6 to 2.11.0 #180.
     </action>
     <action type="update" dev="ggregory" due-to="Dependabot">
-      Update actions/checkout from v1 to v2.3.5 #166 #173 #183 #193 #262.
+      Update actions/checkout from v1 to v2.4.0 #166 #173 #183 #193 #262 #264.
     </action>
     <action type="update" dev="ggregory" due-to="Dependabot">
       Update maven-pmd-plugin from 3.12.0 to 3.15.0 #167 #196 #253.