fix!: deleted styles without associated classes from css.ts, issue #8285 (#8465)

core/css.ts

@@ -134,18 +134,6 @@ let content = `
   border-color: inherit;
 }
 
-.blocklyDropDownButton {
-  display: inline-block;
-  float: left;
-  padding: 0;
-  margin: 4px;
-  border-radius: 4px;
-  outline: none;
-  border: 1px solid;
-  transition: box-shadow .1s;
-  cursor: pointer;
-}
-
 .blocklyArrowTop {
   border-top: 1px solid;
   border-left: 1px solid;
@@ -160,21 +148,6 @@ let content = `
   border-color: inherit;
 }
 
-.blocklyResizeSE {
-  cursor: se-resize;
-  fill: #aaa;
-}
-
-.blocklyResizeSW {
-  cursor: sw-resize;
-  fill: #aaa;
-}
-
-.blocklyResizeLine {
-  stroke: #515A5A;
-  stroke-width: 1;
-}
-
 .blocklyHighlightedConnectionPath {
   fill: none;
   stroke: #fc3;
@@ -270,10 +243,6 @@ let content = `
   cursor: inherit;
 }
 
-.blocklyHidden {
-  display: none;
-}
-
 .blocklyFieldDropdown:not(.blocklyHidden) {
   display: block;
 }