Bump versions.grpc from 1.69.1 to 1.70.0

Bumps `versions.grpc` from 1.69.1 to 1.70.0.

Updates `io.grpc:grpc-bom` from 1.69.1 to 1.70.0
- [Release notes](https://github.com/grpc/grpc-java/releases)
- [Commits](grpc/grpc-java@v1.69.1...v1.70.0)

Updates `io.grpc:protoc-gen-grpc-java` from 1.69.1 to 1.70.0
- [Release notes](https://github.com/grpc/grpc-java/releases)
- [Commits](grpc/grpc-java@v1.69.1...v1.70.0)

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

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

build.gradle

@@ -36,7 +36,7 @@ allprojects {
   ext {
     versions = [
       wiremock: "3.10.0",
-      grpc    : "1.69.1",
+      grpc    : "1.70.0",
       protobuf: "3.25.5"
     ]