fix(cli): remove exp scaletest from slim binary (#9934)

- Removes the `exp scaletest` command from the slim binary 
- Updates scaletest-runner template to fetch the full binary from the running Coder instance

cli/exp_scaletest.go

@@ -1,3 +1,5 @@
+//go:build !slim
+
 package cli
 
 import (

cli/exp_scaletest_slim.go

@@ -0,0 +1,18 @@
+//go:build slim
+
+package cli
+
+import "github.com/coder/coder/v2/cli/clibase"
+
+func (r *RootCmd) scaletestCmd() *clibase.Cmd {
+	cmd := &clibase.Cmd{
+		Use:   "scaletest",
+		Short: "Run a scale test against the Coder API",
+		Handler: func(inv *clibase.Invocation) error {
+			SlimUnsupported(inv.Stderr, "exp scaletest")
+			return nil
+		},
+	}
+
+	return cmd
+}