chore(deps): bump grpc from 1.72.0 to 1.73.0 in /hiero-dependency-versions (#2354)

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Author: dependabot[bot]

hiero-dependency-versions/build.gradle.kts

@@ -9,7 +9,7 @@ plugins {
 group = "org.hiero"
 
 val bouncycastle = "1.80"
-val grpc = "1.72.0"
+val grpc = "1.73.0"
 val protobuf = "4.31.1"
 val slf4j = "2.0.17"
 val mockito = "5.18.0"