Bump creekVersion from 0.3.1-SNAPSHOT to 0.3.1

Bumps `creekVersion` from 0.3.1-SNAPSHOT to 0.3.1.

Updates `org.creekservice:creek-test-hamcrest` from 0.3.1-SNAPSHOT to 0.3.1
- [Release notes](https://github.com/creek-service/creek-test/releases)
- [Commits](https://github.com/creek-service/creek-test/commits/v0.3.1)

Updates `org.creekservice:creek-test-util` from 0.3.1-SNAPSHOT to 0.3.1
- [Release notes](https://github.com/creek-service/creek-test/releases)
- [Commits](https://github.com/creek-service/creek-test/commits/v0.3.1)

Updates `org.creekservice:creek-test-conformity` from 0.3.1-SNAPSHOT to 0.3.1
- [Release notes](https://github.com/creek-service/creek-test/releases)
- [Commits](https://github.com/creek-service/creek-test/commits/v0.3.1)

Updates `org.creekservice:creek-base-type` from 0.3.1-SNAPSHOT to 0.3.1
- [Release notes](https://github.com/creek-service/creek-base/releases)
- [Commits](https://github.com/creek-service/creek-base/commits/v0.3.1)

Updates `org.creekservice:creek-observability-logging` from 0.3.1-SNAPSHOT to 0.3.1
- [Release notes](https://github.com/creek-service/creek-observability/releases)
- [Commits](https://github.com/creek-service/creek-observability/commits/v0.3.1)

---
updated-dependencies:
- dependency-name: org.creekservice:creek-test-hamcrest
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.creekservice:creek-test-util
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.creekservice:creek-test-conformity
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.creekservice:creek-base-type
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.creekservice:creek-observability-logging
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

build.gradle.kts

@@ -25,7 +25,7 @@ subprojects {
     }
 
     extra.apply {
-        set("creekVersion", "0.3.1-SNAPSHOT")
+        set("creekVersion", "0.3.1")
         set("spotBugsVersion", "4.6.0")         // https://mvnrepository.com/artifact/com.github.spotbugs/spotbugs-annotations
 
         set("log4jVersion", "2.19.0")           // https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core