niv motoko-base: update 4abc98e9 -> f7fe9132 (#4703)

## Changelog for motoko-base:
Branch: next-moc
Commits: [dfinity/motoko-base@4abc98e9...f7fe9132](dfinity/motoko-base@4abc98e...f7fe913)

* [`0969b3f0`](dfinity/motoko-base@0969b3f) Motoko 0.13.0
* [`95cbd217`](dfinity/motoko-base@95cbd21) chore(deps-dev): bump express from 4.19.2 to 4.21.0 ([dfinity/motoko-base⁠#660](https://github.com/dfinity/motoko-base/issues/660))
* [`e71081be`](dfinity/motoko-base@e71081b) chore(deps-dev): bump elliptic from 6.5.4 to 6.5.7 ([dfinity/motoko-base⁠#659](https://github.com/dfinity/motoko-base/issues/659))

nix/sources.json

@@ -75,10 +75,10 @@
         "homepage": "",
         "owner": "dfinity",
         "repo": "motoko-base",
-        "rev": "4abc98e92909d7b178629912057473302cf0d8be",
-        "sha256": "09yhfk17rb9xk2cvi6353hfb43df05pg0x1gw5qrf8n0g0dvd3jx",
+        "rev": "f7fe91321ccfea1bce017fbf0d5421ceafa57acb",
+        "sha256": "1vin4s74d8w2pyi6zipbqrvz2k621a4705fc0sshjd23rkd35fn1",
         "type": "tarball",
-        "url": "https://github.com/dfinity/motoko-base/archive/4abc98e92909d7b178629912057473302cf0d8be.tar.gz",
+        "url": "https://github.com/dfinity/motoko-base/archive/f7fe91321ccfea1bce017fbf0d5421ceafa57acb.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "motoko-matchers": {