refactor: remove outdated code

src/themes/_index.scss

@@ -1,49 +0,0 @@
-$black: (
-    50: #000,
-    100: #000,
-    200: #000,
-    300: #000,
-    400: #000,
-    500: #000,
-    600: #000,
-    700: #000,
-    800: #000,
-    900: #000,
-    A100: #000,
-    A200: #000,
-    A400: #000,
-    A700: #000,
-    contrast: (
-        50: $light-primary-text,
-        100: $light-primary-text,
-        200: $light-primary-text,
-        300: $light-primary-text,
-        400: $light-primary-text,
-        500: $light-primary-text,
-        600: $light-primary-text,
-        700: $light-primary-text,
-        800: $light-primary-text,
-        900: $light-primary-text,
-        A100: $light-primary-text,
-        A200: $light-primary-text,
-        A400: $light-primary-text,
-        A700: $light-primary-text,
-    ),
-);
-
-$angular-primary: mat-palette($black);
-$angular-accent: mat-palette($mat-indigo, 500, 600, 700);
-$angular-warn: mat-palette($mat-red);
-$angular-default-theme: mat-light-theme(
-    (
-        color: (
-            primary: $angular-primary,
-            accent: $angular-accent,
-            warn: $angular-warn,
-        ),
-    )
-);
-
-@import 'dark';
-
-@include angular-material-theme($angular-default-theme);

src/themes/dark.scss

@@ -1,20 +0,0 @@
-$dark-primary: mat-palette($black, A200, A700, 500);
-$dark-accent: mat-palette($mat-teal, A400, A100, A400);
-$dark-warn: mat-palette($mat-red);
-$dark-theme: mat-dark-theme(
-    (
-        color: (
-            primary: $dark-primary,
-            accent: $dark-accent,
-            warn: $dark-warn,
-        ),
-    )
-);
-
-.dark-theme {
-    @include angular-material-color($dark-theme);
-
-    a {
-        color: #a5a7fb;
-    }
-}