build(deps-dev): bump version.spockframework

Bumps `version.spockframework` from 2.4-M1-groovy-4.0 to 2.4-M2-groovy-4.0.

Updates `org.spockframework:spock-core` from 2.4-M1-groovy-4.0 to 2.4-M2-groovy-4.0
- [Release notes](https://github.com/spockframework/spock/releases)
- [Changelog](https://github.com/spockframework/spock/blob/master/docs/release_notes.adoc)
- [Commits](https://github.com/spockframework/spock/commits)

Updates `org.spockframework:spock-spring` from 2.4-M1-groovy-4.0 to 2.4-M2-groovy-4.0
- [Release notes](https://github.com/spockframework/spock/releases)
- [Changelog](https://github.com/spockframework/spock/blob/master/docs/release_notes.adoc)
- [Commits](https://github.com/spockframework/spock/commits)

---
updated-dependencies:
- dependency-name: org.spockframework:spock-core
  dependency-type: direct:development
- dependency-name: org.spockframework:spock-spring
  dependency-type: direct:development
...

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

pom.xml

@@ -73,7 +73,7 @@
 
         <version.jbehave>5.0</version.jbehave>
         <version.jbehave-junit-support>5.0.1</version.jbehave-junit-support>
-        <version.spockframework>2.4-M1-groovy-4.0</version.spockframework>
+        <version.spockframework>2.4-M2-groovy-4.0</version.spockframework>
         <version.sshj>0.38.0</version.sshj>
         <version.commons-text>1.9</version.commons-text>
         <version.commons-collections4>4.4</version.commons-collections4>