pylint: fix useless-return

A bare return at the end of a function doesn't do anything. And in the
case of a try/except, it's really just an elaborate "pass" anyway.
diff --git a/mesonbuild/ast/introspection.py b/mesonbuild/ast/introspection.py
index 5bf7e05..fa11feb 100644
--- a/mesonbuild/ast/introspection.py
+++ b/mesonbuild/ast/introspection.py
@@ -145,7 +145,7 @@
             subi.project_data['name'] = dirname
             self.project_data['subprojects'] += [subi.project_data]
         except (mesonlib.MesonException, RuntimeError):
-            return
+            pass
 
     def func_add_languages(self, node: BaseNode, args: T.List[TYPE_var], kwargs: T.Dict[str, TYPE_var]) -> None:
         kwargs = self.flatten_kwargs(kwargs)
diff --git a/mesonbuild/dependencies/misc.py b/mesonbuild/dependencies/misc.py
index fd59652..72c7cf0 100644
--- a/mesonbuild/dependencies/misc.py
+++ b/mesonbuild/dependencies/misc.py
@@ -422,7 +422,6 @@
             if self.static:
                 if not self._add_sub_dependency(iconv_factory(env, self.for_machine, {'static': True})):
                     self.is_found = False
-                    return
 
 
 class OpensslSystemDependency(SystemDependency):