pythonPackages.nilearn: disable still failing tests (#46918)

A previous attempt to fix tests failing on some machines (#46850)
was unsuccessful, they still failed on Hydra sometimes while
succeeding locally. Revert #46850 and disable these tests instead.

(cherry picked from commit f3a0c8a)

pkgs/development/python-modules/nilearn/default.nix

@@ -14,18 +14,12 @@ buildPythonPackage rec {
   # disable some failing tests
   checkPhase = ''
     nosetests nilearn/tests \
-    -e test_cache_mixin_with_expand_user -e test_clean_confounds -e test_detrend
+    -e test_cache_mixin_with_expand_user -e test_clean_confounds -e test_detrend \
+    -e test_clean_detrending -e test_high_variance_confounds
   '';
 
   checkInputs = [ nose ];
 
-  # These tests fail on some builder machines, probably due to lower
-  # arithmetic precision. Reduce required precision from 13 to 8 decimals.
-  postPatch = ''
-    substituteInPlace nilearn/tests/test_signal.py \
-      --replace 'decimal=13' 'decimal=8'
-  '';
-
   propagatedBuildInputs = [
     matplotlib
     nibabel