Bump junit.version from 5.10.2 to 5.10.3

Bumps `junit.version` from 5.10.2 to 5.10.3.

Updates `org.junit.jupiter:junit-jupiter-api` from 5.10.2 to 5.10.3
- [Release notes](https://github.com/junit-team/junit5/releases)
- [Commits](junit-team/junit5@r5.10.2...r5.10.3)

Updates `org.junit.jupiter:junit-jupiter-engine` from 5.10.2 to 5.10.3
- [Release notes](https://github.com/junit-team/junit5/releases)
- [Commits](junit-team/junit5@r5.10.2...r5.10.3)

---
updated-dependencies:
- dependency-name: org.junit.jupiter:junit-jupiter-api
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.junit.jupiter:junit-jupiter-engine
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

pom.xml

@@ -36,7 +36,7 @@
     <com.io7m.xstructural.version>1.8.1</com.io7m.xstructural.version>
 
     <!-- Third-party dependencies. -->
-    <junit.version>5.10.2</junit.version>
+    <junit.version>5.10.3</junit.version>
     <org.immutables.value.version>2.10.1</org.immutables.value.version>
   </properties>