refactor: lint and tests

Author: andrewseguin

src/material/core/theming/_theming.scss

@@ -4,6 +4,10 @@
 @use 'sass:meta';
 @use 'sass:color';
 
+// Deprecated flag that is no longer used to control duplication warnings.
+// Remove in v22
+$theme-ignore-duplication-warnings: false;
+
 // Whether to enable compatibility with legacy methods for accessing theme information.
 $theme-legacy-inspection-api-compatibility: true !default;
 

src/material/core/theming/tests/test-theming-api.scss

@@ -9,10 +9,6 @@
 @use '../theming';
 @use 'sass:map';
 
-// Disable theme style duplication warnings. This test intentionally generates
-// the same themes multiple times.
-theming.$theme-ignore-duplication-warnings: true;
-
 // A new way to configure themes has been introduced. This Sass file ensures that the theming
 // API is backwards compatible, so that the old pattern for configuring themes can be still
 // used. The Sass compilation of this file will fail if one of the tests/assertions fails.

src/material/core/theming/tests/test-theming-bundle.scss

@@ -3,10 +3,6 @@
 // with the include paths being set to the `bazel-bin` directory.
 @use '../../../index' as mat;
 
-// Disable theme style duplication warnings. This test intentionally generates
-// the same themes multiple times.
-mat.$theme-ignore-duplication-warnings: true;
-
 // If one of these mixins or function is not available, the compilation will fail and the
 // test will be reported as failing.