Change version to 1.79.0-dev (#8763)

RELEASE NOTES: N/A
diff --git a/version.go b/version.go
index a9e1f11..b35e1cb 100644
--- a/version.go
+++ b/version.go
@@ -19,4 +19,4 @@
 package grpc
 
 // Version is the current grpc version.
-const Version = "1.78.0-dev"
+const Version = "1.79.0-dev"