Bump grpc.version from 1.68.1 to 1.70.0 (#3678)

Bumps `grpc.version` from 1.68.1 to 1.70.0.

Updates `io.grpc:grpc-netty` from 1.68.1 to 1.70.0
- [Release notes](https://github.com/grpc/grpc-java/releases)
- [Commits](https://github.com/grpc/grpc-java/compare/v1.68.1...v1.70.0)

Updates `io.grpc:grpc-protobuf` from 1.68.1 to 1.70.0
- [Release notes](https://github.com/grpc/grpc-java/releases)
- [Commits](https://github.com/grpc/grpc-java/compare/v1.68.1...v1.70.0)

Updates `io.grpc:grpc-stub` from 1.68.1 to 1.70.0
- [Release notes](https://github.com/grpc/grpc-java/releases)
- [Commits](https://github.com/grpc/grpc-java/compare/v1.68.1...v1.70.0)

---
updated-dependencies:
- 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
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

spring-cloud-gateway-integration-tests/grpc/pom.xml

@@ -12,7 +12,7 @@
 
 	<properties>
 		<protoc.version>3.25.1</protoc.version>
-		<grpc.version>1.68.1</grpc.version>
+		<grpc.version>1.70.0</grpc.version>
 	</properties>
 
 	<parent>

spring-cloud-gateway-server/pom.xml

@@ -16,7 +16,7 @@
 	<description>Spring Cloud Gateway Server</description>
 	<properties>
 		<main.basedir>${basedir}/..</main.basedir>
-		<grpc.version>1.68.1</grpc.version>
+		<grpc.version>1.70.0</grpc.version>
 		<context-propagation.version>1.0.0</context-propagation.version>
 	</properties>