Remove extra background color from the table view (#2425)

Author: shcheklein

webview/src/experiments/components/table/styles.module.scss

@@ -287,7 +287,6 @@ $workspace-row-edge-margin: $edge-padding - $cell-padding;
   .tableContainer {
     overflow: auto;
     flex: 1;
-    background-color: $experiments-view-bg-color;
   }
   .table {
     display: inline-block;

webview/src/shared/variables.scss

@@ -10,7 +10,6 @@ $deps-color: var(--vscode-dvc-deps);
 $changed-color: var(--vscode-dvc-workspaceChanged);
 $error-color: var(--vscode-errorForeground);
 
-$experiments-view-bg-color: var(--vscode-menu-background);
 $row-bg-color: $bg-color;
 $header-fg-color: $fg-color;
 $row-bg-alt-color: var(--vscode-sideBar-background);