Bump versions.grpc from 1.68.0 to 1.68.2

Bumps `versions.grpc` from 1.68.0 to 1.68.2.

Updates `io.grpc:grpc-bom` from 1.68.0 to 1.68.2
- [Release notes](https://github.com/grpc/grpc-java/releases)
- [Commits](grpc/grpc-java@v1.68.0...v1.68.2)

Updates `io.grpc:protoc-gen-grpc-java` from 1.68.0 to 1.68.2
- [Release notes](https://github.com/grpc/grpc-java/releases)
- [Commits](grpc/grpc-java@v1.68.0...v1.68.2)

---
updated-dependencies:
- dependency-name: io.grpc:grpc-bom
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: io.grpc:protoc-gen-grpc-java
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

build.gradle

@@ -36,7 +36,7 @@ allprojects {
   ext {
     versions = [
       wiremock: "3.10.0",
-      grpc    : "1.68.0",
+      grpc    : "1.68.2",
       protobuf: "3.25.5"
     ]