MINOR: Bump io.grpc:grpc-bom from 1.73.0 to 1.78.0

Bumps [io.grpc:grpc-bom](https://github.com/grpc/grpc-java) from 1.73.0 to 1.78.0.
- [Release notes](https://github.com/grpc/grpc-java/releases)
- [Commits](grpc/grpc-java@v1.73.0...v1.78.0)

---
updated-dependencies:
- dependency-name: io.grpc:grpc-bom
  dependency-version: 1.78.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

pom.xml

@@ -98,7 +98,7 @@ under the License.
     <dep.slf4j.version>2.0.17</dep.slf4j.version>
     <dep.guava-bom.version>33.4.8-jre</dep.guava-bom.version>
     <dep.netty-bom.version>4.2.9.Final</dep.netty-bom.version>
-    <dep.grpc-bom.version>1.73.0</dep.grpc-bom.version>
+    <dep.grpc-bom.version>1.78.0</dep.grpc-bom.version>
     <dep.protobuf-bom.version>4.33.1</dep.protobuf-bom.version>
     <dep.jackson-bom.version>2.18.3</dep.jackson-bom.version>
     <dep.hadoop.version>3.4.2</dep.hadoop.version>