pylint: Catch cases of `if len(container)` which should be replaced by `if container`

Unfortunately this doesn't catch other abuses of len(continauer) like,
`len(container) <comparator> 0`, see: https://github.com/PyCQA/pylint/issues/3751

.pylintrc

@@ -6,4 +6,6 @@ score=no
 
 [MESSAGES CONTROL]
 disable=all
-enable=unreachable
+enable=
+    len-as-condition,
+    unreachable

mesonbuild/backend/ninjabackend.py

@@ -2587,7 +2587,7 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
 
     def get_link_whole_args(self, linker, target):
         target_args = self.build_target_link_arguments(linker, target.link_whole_targets)
-        return linker.get_link_whole_for(target_args) if len(target_args) else []
+        return linker.get_link_whole_for(target_args) if target_args else []
 
     @lru_cache(maxsize=None)
     def guess_library_absolute_path(self, linker, libname, search_dirs, patterns):

mesonbuild/build.py

@@ -2232,7 +2232,7 @@ class CustomTarget(Target):
     def get_dep_outname(self, infilenames):
         if self.depfile is None:
             raise InvalidArguments('Tried to get depfile name for custom_target that does not have depfile defined.')
-        if len(infilenames):
+        if infilenames:
             plainname = os.path.basename(infilenames[0])
             basename = os.path.splitext(plainname)[0]
             return self.depfile.replace('@BASENAME@', basename).replace('@PLAINNAME@', plainname)