MDL-77559 js: Revert "MDL-75012 js: Bump shifter to new version"

This reverts commit b3f7721.

Author: andrewnicols

npm-shrinkwrap.json

@@ -41,7 +41,7 @@
     "postcss-scss": "^4.0.6",
     "rollup-plugin-terser": "^7.0.2",
     "semver": "^7.3.8",
-    "shifter": "https://github.com/andrewnicols/shifter/releases/download/v1.2.0_moodle-1/shifter-1.2.0_moodle-1.tar.gz",
+    "shifter": "https://github.com/andrewnicols/shifter/archive/v1.2.0_moodle-0.tar.gz",
     "stylelint": "^14.16.1",
     "stylelint-csstree-validator": "^2.1.0",
     "xmldom": "^0.6.0",