scripted-diff: Remove obsolete comment

The removed comment become obsolete after bitcoin/bitcoin#32697 and
bitcoin/bitcoin#32881.

-BEGIN VERIFY SCRIPT-

sed -i "s/ Some tests are disabled if Python 3 is not available.//g" \
$( git grep -l " Some tests are disabled if Python 3 is not available." ./doc/ )

-END VERIFY SCRIPT-

doc/build-netbsd.md

@@ -115,5 +115,5 @@ Build and run the tests:
 
 ```bash
 cmake --build build     # Append "-j N" for N parallel jobs.
-ctest --test-dir build  # Append "-j N" for N parallel tests. Some tests are disabled if Python 3 is not available.
+ctest --test-dir build  # Append "-j N" for N parallel tests.
 ```