envutil: add GOMEMLIMIT to safeVarRegistry

This commit adds the GOMEMLIMIT environment variable to the list of go
runtime env vars that Cockroach will report about on the Node Diagnostics
page. The original set was added in f6e2313. Since then, this is the only
env var added to the go runtime.

Release note: None

Epic: None

pkg/util/envutil/env.go

@@ -186,10 +186,12 @@ func GetEnvVarsUsed() (result []redact.RedactableString) {
 // the name and the value safely: the value is known to never contain
 // sensitive information.
 var safeVarRegistry = map[redact.SafeString]struct{}{
+	// Go runtime.
 	"GOGC":        {},
 	"GODEBUG":     {},
 	"GOMAXPROCS":  {},
 	"GOTRACEBACK": {},
+	"GOMEMLIMIT":  {},
 	// gRPC.
 	"GRPC_GO_LOG_SEVERITY_LEVEL":  {},
 	"GRPC_GO_LOG_VERBOSITY_LEVEL": {},