Upgrade @microbit/ui to 0.1.0-alpha.9; restore reference select's sm size

The alternatives select in reference documentation was size="sm" under
Chakra; the port dropped it while the input recipe was single-size.
alpha.9 also fixes the invisible unselected checkbox border and copy
buttons in unpermissioned/insecure contexts (useClipboard fallback).

Author: microbit-matt-hillsdon

package-lock.json

@@ -20,8 +20,8 @@
     "@codemirror/state": "^6.4.1",
     "@codemirror/view": "^6.26.3",
     "@microbit/microbit-connection": "^1.0.0",
-    "@microbit/ui": "0.1.0-alpha.8",
     "@microbit/microbit-fs": "^0.10.0",
+    "@microbit/ui": "0.1.0-alpha.9",
     "@sanity/block-content-to-react": "^3.0.0",
     "@sanity/image-url": "^1.0.1",
     "@testing-library/jest-dom": "^5.14.1",

package.json

@@ -140,6 +140,7 @@ const ReferenceTopicEntry = ({
                   css={{ width: "fit-content" }}
                   onChange={handleSelectChange}
                   value={alternativeSlug}
+                  size="sm"
                 >
                   {alternatives.map((alterative) => (
                     <option