Fix: spurious deprecation warnings in scss code

move the deprecation `@includes` inside the css rule

completes issue #979

Author: arikorn

scss/mixins/_alert.scss

@@ -1,10 +1,9 @@
 @use "../variables" as *;
 @use "../mixins/deprecate" as *;
 
-@include deprecate("`alert-variant()`", "v4.3.0", "v6.0.0");
-
 // scss-docs-start alert-variant-mixin
 @mixin alert-variant($background, $border, $color) {
+  @include deprecate("`alert-variant()`", "v4.3.0", "v6.0.0");
   --#{$prefix}alert-color: #{$color};
   --#{$prefix}alert-bg: #{$background};
   --#{$prefix}alert-border-color: #{$border};

scss/mixins/_avatar.scss

@@ -1,9 +1,8 @@
 @use "../variables" as *;
 @use "../mixins/deprecate" as *;
 
-@include deprecate("`avatar()`", "v5.1.0", "v6.0.0");
-
 @mixin avatar($width) {
+  @include deprecate("`avatar()`", "v5.1.0", "v6.0.0");
   --#{$prefix}avatar-width: #{$width};
   --#{$prefix}avatar-height: #{$width};
   --#{$prefix}avatar-font-size: #{$width * .4};

scss/mixins/_list-group.scss

@@ -1,12 +1,11 @@
 @use "sass:map";
 @use "../mixins/deprecate" as *;
 
-@include deprecate("`list-group-item-variant()`", "v4.3.0", "v6.0.0");
-
 // List Groups
 
 // scss-docs-start list-group-mixin
 @mixin list-group-item-variant($state, $variant) {
+  @include deprecate("`list-group-item-variant()`", "v4.3.0", "v6.0.0");
   $background: map.get($variant, "bg");
   $background-hover: map.get($variant, "bg-hover");
   $color: contrast-ratio-correction(map.get($variant, "color"), map.get($variant, "bg"), $alert-color-scale, $state);