[botanist] Remove default config file name.

We want to remove code that is related to infra.

Bug: 10321
Change-Id: I85c5da9f8df15d153c9117c3de6c8e54672dba92
diff --git a/botanist/cmd/run.go b/botanist/cmd/run.go
index c88134f..3845982 100644
--- a/botanist/cmd/run.go
+++ b/botanist/cmd/run.go
@@ -109,7 +109,7 @@
 }
 
 func (r *RunCommand) SetFlags(f *flag.FlagSet) {
-	f.StringVar(&r.configFile, "config", "/etc/botanist/device.json", "path to file of device config")
+	f.StringVar(&r.configFile, "config", "", "path to file of device config")
 	f.Var(&r.imageManifests, "images", "paths to image manifests")
 	f.BoolVar(&r.netboot, "netboot", false, "if set, botanist will not pave; but will netboot instead")
 	f.Var(&r.zirconArgs, "zircon-args", "kernel command-line arguments")
diff --git a/botanist/cmd/zedboot.go b/botanist/cmd/zedboot.go
index a5bfbae..a8f6799 100644
--- a/botanist/cmd/zedboot.go
+++ b/botanist/cmd/zedboot.go
@@ -72,7 +72,7 @@
 	f.StringVar(&cmd.outputArchive, "out", "output.tar", "path on host to output tarball of test results")
 	f.StringVar(&cmd.summaryFilename, "summary-name", runtests.TestSummaryFilename, "name of the file in the test directory")
 	f.DurationVar(&cmd.filePollInterval, "poll-interval", 1*time.Minute, "time between checking for summary.json on the target")
-	f.StringVar(&cmd.configFile, "config", "/etc/botanist/config.json", "path to file of device config")
+	f.StringVar(&cmd.configFile, "config", "", "path to file of device config")
 	f.StringVar(&cmd.cmdlineFile, "cmdline-file", "", "path to a file containing additional kernel command-line arguments")
 }