Bump org.jlleitschuh.gradle.ktlint in /kotlin-project

Bumps org.jlleitschuh.gradle.ktlint from 11.6.1 to 12.1.2.

---
updated-dependencies:
- dependency-name: org.jlleitschuh.gradle.ktlint
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

kotlin-project/build.gradle.kts

@@ -1,6 +1,6 @@
 plugins {
     kotlin("jvm") version "1.9.24"
-    id("org.jlleitschuh.gradle.ktlint") version "11.6.1"
+    id("org.jlleitschuh.gradle.ktlint") version "12.1.2"
     id("com.coditory.build") version "0.1.20"
 }