fix(node-build-scripts): Update variables.less test fixture (#7634)

Author: ggdouglas

packages/node-build-scripts/src/__tests__/__fixtures__/expected/variables.less

@@ -4,8 +4,8 @@
 
 @ns: bp4;
 @icons16-family: "blueprint-icons-16";
-@pt-font-family: -apple-system, "BlinkMacSystemFont", "Segoe UI", "Roboto", "Oxygen", "Ubuntu", "Cantarell", "Open Sans",
-    "Helvetica Neue", "blueprint-icons-16", sans-serif;
+@pt-font-family: -apple-system, "BlinkMacSystemFont", "Segoe UI", "Roboto", "Oxygen", "Ubuntu", "Cantarell",
+    "Open Sans", "Helvetica Neue", "blueprint-icons-16", sans-serif;
 @pt-border-radius: 2px;
 @black: #111418;
 @gray1: #5f6b7c;