niv motoko-base: update 86a99923 -> 22ef8ef1 (#4495)

## Changelog for motoko-base:
Branch: next-moc
Commits: [dfinity/motoko-base@86a99923...22ef8ef1](dfinity/motoko-base@86a9992...22ef8ef)

* [`25d7085f`](dfinity/motoko-base@25d7085) fix: un-deprecate array append + CI sanity check ([dfinity/motoko-base⁠#630](https://togithub.com/dfinity/motoko-base/issues/630))

nix/sources.json

@@ -75,10 +75,10 @@
         "homepage": null,
         "owner": "dfinity",
         "repo": "motoko-base",
-        "rev": "86a99923f69a7c46085b8b4ffbc5748725920c6f",
-        "sha256": "1a6pvavjshyxhm5859zys76n0sw83wx3bigs90vqvr5nv5aw1189",
+        "rev": "22ef8ef1c8ddab4e059881ad75869b827a878292",
+        "sha256": "0w6qizw4j2srkm1l8qcwqxp55q9ymprbaf56b9k4pk60gal3nkl5",
         "type": "tarball",
-        "url": "https://github.com/dfinity/motoko-base/archive/86a99923f69a7c46085b8b4ffbc5748725920c6f.tar.gz",
+        "url": "https://github.com/dfinity/motoko-base/archive/22ef8ef1c8ddab4e059881ad75869b827a878292.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "motoko-matchers": {