Bump io.mockk:mockk from 1.12.5 to 1.13.8

Bumps [io.mockk:mockk](https://github.com/mockk/mockk) from 1.12.5 to 1.13.8.
- [Release notes](https://github.com/mockk/mockk/releases)
- [Commits](mockk/mockk@1.12.5...1.13.8)

---
updated-dependencies:
- dependency-name: io.mockk:mockk
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

build.gradle

@@ -64,7 +64,7 @@ dependencies {
     implementation "com.zaxxer:HikariCP:5.0.1"
 
     testImplementation "io.ktor:ktor-server-tests:$ktor_version"
-    testImplementation "io.mockk:mockk:1.12.5"
+    testImplementation "io.mockk:mockk:1.13.8"
     testImplementation "org.json:json:20220320"
 
 }