build(deps): bump grpc from 1.66.0 to 1.68.0

Bumps `grpc` from 1.66.0 to 1.68.0.

Updates `io.grpc:grpc-core` from 1.66.0 to 1.68.0
- [Release notes](https://github.com/grpc/grpc-java/releases)
- [Commits](https://github.com/grpc/grpc-java/commits)

Updates `io.grpc:grpc-netty` from 1.66.0 to 1.68.0
- [Release notes](https://github.com/grpc/grpc-java/releases)
- [Commits](https://github.com/grpc/grpc-java/commits)

Updates `io.grpc:grpc-protobuf` from 1.66.0 to 1.68.0
- [Release notes](https://github.com/grpc/grpc-java/releases)
- [Commits](https://github.com/grpc/grpc-java/commits)

Updates `io.grpc:grpc-stub` from 1.66.0 to 1.68.0
- [Release notes](https://github.com/grpc/grpc-java/releases)
- [Commits](https://github.com/grpc/grpc-java/commits)

Updates `io.grpc:grpc-grpclb` from 1.66.0 to 1.68.0
- [Release notes](https://github.com/grpc/grpc-java/releases)
- [Commits](https://github.com/grpc/grpc-java/commits)

Updates `io.grpc:grpc-inprocess` from 1.66.0 to 1.68.0
- [Release notes](https://github.com/grpc/grpc-java/releases)
- [Commits](https://github.com/grpc/grpc-java/commits)

Updates `io.grpc:grpc-util` from 1.66.0 to 1.68.0
- [Release notes](https://github.com/grpc/grpc-java/releases)
- [Commits](https://github.com/grpc/grpc-java/commits)

---
updated-dependencies:
- dependency-name: io.grpc:grpc-core
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: io.grpc:grpc-netty
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: io.grpc:grpc-protobuf
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: io.grpc:grpc-stub
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: io.grpc:grpc-grpclb
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: io.grpc:grpc-inprocess
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: io.grpc:grpc-util
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

gradle/libs.versions.toml

@@ -1,5 +1,5 @@
 [versions]
-grpc = "1.66.0"
+grpc = "1.68.0"
 log4j = "2.23.1"
 mockito = "5.13.0"
 slf4j = "2.0.16"