chore(deps): bump kotlin.version from 2.0.20 to 2.1.0 in /kotlin-routes (#1596)

Bumps `kotlin.version` from 2.0.20 to 2.1.0.

Updates `org.jetbrains.kotlin:kotlin-maven-allopen` from 2.0.20 to 2.1.0

Updates `org.jetbrains.kotlin:kotlin-maven-plugin` from 2.0.20 to 2.1.0

---
updated-dependencies:
- dependency-name: org.jetbrains.kotlin:kotlin-maven-allopen
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: org.jetbrains.kotlin:kotlin-maven-plugin
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]