Bump kotlin.version from 2.0.21 to 2.1.0

Bumps `kotlin.version` from 2.0.21 to 2.1.0.

Updates `org.jetbrains.kotlin:kotlin-maven-allopen` from 2.0.21 to 2.1.0

Updates `org.jetbrains.kotlin:kotlin-maven-plugin` from 2.0.21 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] <support@github.com>

grpc-locations/pom.xml

@@ -10,7 +10,7 @@
   <properties>
     <assertj.version>3.26.3</assertj.version>
     <compiler-plugin.version>3.13.0</compiler-plugin.version>
-    <kotlin.version>2.0.21</kotlin.version>
+    <kotlin.version>2.1.0</kotlin.version>
     <maven.compiler.release>21</maven.compiler.release>
     <mockk.version>3.0.0</mockk.version>
     <jacoco.version>0.8.12</jacoco.version>