cmd/go: add missing cgo condition in TestScript/mod_list_compiled_concurrent

Updates #50205

Change-Id: I60d2e32c2cd84599f4a0126e4da4f1d61bd29b51
Reviewed-on: https://go-review.googlesource.com/c/go/+/372799
Trust: Bryan Mills <[email protected]>
Run-TryBot: Bryan Mills <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
Reviewed-by: Ian Lance Taylor <[email protected]>

Author: Bryan C. Mills

src/cmd/go/testdata/script/mod_list_compiled_concurrent.txt

@@ -1,6 +1,7 @@
 env GO111MODULE=on
 
 [short] skip
+[!cgo] skip
 
 # Regression test for golang.org/issue/29667:
 # spurious 'failed to cache compiled Go files' errors.