fix: upgrade io.grpc:grpc-protobuf from 1.66.0 to 1.68.0

Snyk has created this PR to upgrade io.grpc:grpc-protobuf from 1.66.0 to 1.68.0.

See this package in maven:
io.grpc:grpc-protobuf

See this project in Snyk:
https://app.snyk.io/org/b.w.donnelly1/project/537d8cdc-cdc5-4851-8ce3-bfc4014a9b50?utm_source=github&utm_medium=referral&page=upgrade-pr

pom.xml

@@ -86,7 +86,7 @@
 
     <properties>
         <deep-proto.version>1.0.5</deep-proto.version>
-        <grpc.version>1.66.0</grpc.version>
+        <grpc.version>1.68.0</grpc.version>
         <netty.version>4.1.112.Final</netty.version>
         <tcnative.version>2.0.65.Final</tcnative.version>
         <asm.version>8.0.1</asm.version>