Bump mockkVersion from 1.12.3 to 1.12.4

Bumps `mockkVersion` from 1.12.3 to 1.12.4.

Updates `mockk` from 1.12.3 to 1.12.4
- [Release notes](https://github.com/mockk/mockk/releases)
- [Commits](https://github.com/mockk/mockk/compare/1.12.3...1.12.4)

Updates `mockk-android` from 1.12.3 to 1.12.4
- [Release notes](https://github.com/mockk/mockk/releases)
- [Commits](https://github.com/mockk/mockk/compare/1.12.3...1.12.4)

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

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

build.gradle

@@ -9,7 +9,7 @@ buildscript {
         androidLibraryVersion = "master-SNAPSHOT"
         mockitoVersion = "4.5.1"
         mockitoKotlinVersion = "4.0.0"
-        mockkVersion = "1.12.3"
+        mockkVersion = "1.12.4"
         powermockVersion = "2.0.9"
         byteBuddyVersion = "1.12.10"
         espressoVersion = "3.4.0"