doc/tutorial/basics: fix example

no no longer matches boolean false in latest YAML

Change-Id: I089600e0eab32cdfebde348a8794ae373b8cd4d7
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/8786
Reviewed-by: CUE cueckoo <cueckoo@gmail.com>
Reviewed-by: Paul Jolly <paul@myitcv.org.uk>

doc/tutorial/basics/0_intro/47_validation.txt

@@ -26,9 +26,6 @@ languages:
     name: Norwegian
 
 -- expect-stderr --
-languages.2.tag: conflicting values string and false (mismatched types string and bool):
-    ./data.yaml:6:11
-    ./schema.cue:2:8
 languages.1.name: invalid value "dutch" (does not match =~"^\\p{Lu}"):
     ./schema.cue:3:8
     ./data.yaml:5:12