ref(css): removed old image styles (#23697)

* ref(css): removed old image styles

* removed image styles from mixins

src/sentry/static/sentry/less/includes/bootstrap/mixins.less

@@ -3,7 +3,6 @@
 
 // Utilities
 @import 'mixins/hide-text.less';
-@import 'mixins/image.less';
 @import 'mixins/labels.less';
 @import 'mixins/reset-filter.less';
 @import 'mixins/resize.less';

src/sentry/static/sentry/less/includes/bootstrap/mixins/image.less

@@ -1,28 +0,0 @@
-// stylelint-disable media-feature-name-no-vendor-prefix, media-feature-parentheses-space-inside, media-feature-name-no-unknown, indentation, at-rule-name-space-after
-
-// Responsive image
-//
-// Keep images from scaling beyond the width of their parents.
-.img-responsive(@display: block) {
-  display: @display;
-  max-width: 100%; // Part 1: Set a maximum relative to the parent
-  height: auto; // Part 2: Scale the height according to the width, otherwise you get stretching
-}
-
-// Retina image
-//
-// Short retina mixin for setting background-image and -size. Note that the
-// spelling of `min--moz-device-pixel-ratio` is intentional.
-.img-retina(@file-1x; @file-2x; @width-1x; @height-1x) {
-  background-image: url('@{file-1x}');
-
-  @media only screen and (-webkit-min-device-pixel-ratio: 2),
-    only screen and (min--moz-device-pixel-ratio: 2),
-    only screen and (-o-min-device-pixel-ratio: 2/1),
-    only screen and (min-device-pixel-ratio: 2),
-    only screen and (min-resolution: 192dpi),
-    only screen and (min-resolution: 2dppx) {
-    background-image: url('@{file-2x}');
-    background-size: @width-1x @height-1x;
-  }
-}

src/sentry/static/sentry/less/includes/bootstrap/scaffolding.less

@@ -1,8 +1,3 @@
-// Responsive images (ensure images don't scale beyond their parents)
-.img-responsive {
-  .img-responsive();
-}
-
 // Rounded corners
 .img-rounded {
   border-radius: @border-radius-large;