build(deps-dev): bump grpc-protobuf.version from 1.68.0 to 1.68.1

Bumps `grpc-protobuf.version` from 1.68.0 to 1.68.1.

Updates `io.grpc:grpc-protobuf` from 1.68.0 to 1.68.1
- [Release notes](https://github.com/grpc/grpc-java/releases)
- [Commits](grpc/grpc-java@v1.68.0...v1.68.1)

Updates `io.grpc:grpc-stub` from 1.68.0 to 1.68.1
- [Release notes](https://github.com/grpc/grpc-java/releases)
- [Commits](grpc/grpc-java@v1.68.0...v1.68.1)

---
updated-dependencies:
- dependency-name: io.grpc:grpc-protobuf
  dependency-type: direct:development
  update-type: version-update:semver-patch
- dependency-name: io.grpc:grpc-stub
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

embedded-spicedb/pom.xml

@@ -13,7 +13,7 @@
     <artifactId>embedded-spicedb</artifactId>
 
     <properties>
-        <grpc-protobuf.version>1.68.0</grpc-protobuf.version>
+        <grpc-protobuf.version>1.68.1</grpc-protobuf.version>
         <authzed.version>0.10.0</authzed.version>
     </properties>