chore(deps): bump google.golang.org/grpc in /magefiles

Bumps [google.golang.org/grpc](https://github.com/grpc/grpc-go) from 1.79.1 to 1.79.3.
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](grpc/grpc-go@v1.79.1...v1.79.3)

---
updated-dependencies:
- dependency-name: google.golang.org/grpc
  dependency-version: 1.79.3
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

magefiles/go.mod

@@ -286,7 +286,7 @@ require (
 	golang.org/x/vuln v1.1.4 // indirect
 	google.golang.org/genproto/googleapis/api v0.0.0-20260226221140-a57be14db171 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20260226221140-a57be14db171 // indirect
-	google.golang.org/grpc v1.79.1 // indirect
+	google.golang.org/grpc v1.79.3 // indirect
 	google.golang.org/grpc/cmd/protoc-gen-go-grpc v1.6.1 // indirect
 	google.golang.org/protobuf v1.36.11 // indirect
 	gopkg.in/ini.v1 v1.67.0 // indirect