niv motoko-base: update 8d5713b2 -> 8fd23fa7 (#4925)

## Changelog for motoko-base:
Branch: next-moc
Commits: [dfinity/motoko-base@8d5713b2...8fd23fa7](dfinity/motoko-base@8d5713b...8fd23fa)

* [`c6e84991`](dfinity/motoko-base@c6e8499) chore(deps-dev): bump elliptic from 6.6.0 to 6.6.1 ([dfinity/motoko-base⁠#690](https://togithub.com/dfinity/motoko-base/issues/690))
* [`537aa3bc`](dfinity/motoko-base@537aa3b) Motoko 0.14.2

Author: dfinity-bot

nix/sources.json

@@ -75,10 +75,10 @@
         "homepage": "",
         "owner": "dfinity",
         "repo": "motoko-base",
-        "rev": "8d5713b2eb75104fb32d3cb988bb6b406e1450bd",
-        "sha256": "1qfhjk8z7dlp15b9c9lil2zx96dj7w0xdgpv152h7g8igzq956as",
+        "rev": "8fd23fa749290e254a6c411659837b3eed905611",
+        "sha256": "1llzpkc3pza5hc0vh4rwais6hf1s554jck12vvv755rgsbn1ypf1",
         "type": "tarball",
-        "url": "https://github.com/dfinity/motoko-base/archive/8d5713b2eb75104fb32d3cb988bb6b406e1450bd.tar.gz",
+        "url": "https://github.com/dfinity/motoko-base/archive/8fd23fa749290e254a6c411659837b3eed905611.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "motoko-matchers": {