Delete unused creds_file flag

Now that caching is moved to the credshelper,
we can delete the creds file flag. This shouldn't
cause any issuse since bootstrap was the only one
setting this flag for reproxy.

Bug: b/332568410
Test: N/A
Change-Id: I7dd5c218ef011c1f3e3192bbac3290917fb3182a
GitOrigin-RevId: 91e0b34bff0c5567c437831b32359c80ef023a28

cmd/reproxy/main.go

@@ -130,7 +130,6 @@ var (
 
 	depsScannerAddress = flag.String("depsscanner_address", "execrel://", "If set, connects to the given address for C++ dependency scanning; a path with the prefix 'exec://' will start the target executable and connect to it. Defaults to execrel:// which looks for the `scandeps_server` binary in the same folder as reproxy. When set to \"\", the internal dependency scanner will be used.")
 
-	credsFile             = flag.String("creds_file", "", "DEPRECATED. Path to file where short-lived credentials are stored. If the file includes a token, reproxy will update the token if it refreshes it. Token refresh is only applicable if use_external_auth_token is used.")
 	waitForShutdownRPC    = flag.Bool("wait_for_shutdown_rpc", false, "If set, will only shutdown after 3 SIGINT signals")
 	logHTTPCalls          = flag.Bool("log_http_calls", false, "Log all http requests made with the default http client.")
 	auxiliaryMetadataPath = flag.String("auxiliary_metadata_path", "", "Path to file where auxiliary_metadata.pb file is stored. Should be a absolute path or a relative path to reproxy.")
@@ -275,11 +274,6 @@ func main() {
 	ctx := context.Background()
 	var ts *grpcOauth.TokenSource
 	if !*remoteDisabled {
-		if *credsFile != "" {
-			// --creds_file flag shouldn't be set anywhere, so this shouldn't come up - since bootstrap was responsible for setting this flag based on the given cache_dir
-			fmt.Fprintf(os.Stderr, "--creds_file flag is invalid now. No credentials are cached. Please unset this flag and try again")
-			os.Exit(1)
-		}
 		chFlag := flag.Lookup(credshelper.CredshelperPathFlag)
 		credentialsHelperPath := chFlag.Value.String()
 		if credentialsHelperPath != "" {