deps: upgrade flake_id to fix crash

Currently FlakeId.flake_id crashes if receiving non-UTF-8 binaries,
but we use it e.g. in the /:nick_or_id path used in akkoma-fe user
profiles.
With the upgrade such invalid binaries simply fail the id check.

Reported-in: https://meta.akkoma.dev/t/frontend-unicodeconversionerror/847

mix.exs

@@ -174,7 +174,9 @@ defp deps do
       {:pot, "~> 1.0"},
       {:ex_const, "~> 0.2"},
       {:plug_static_index_html, "~> 1.0.0"},
-      {:flake_id, "~> 0.1.0"},
+      {:flake_id,
+       git: "https://akkoma.dev/AkkomaGang/flake_id.git",
+       ref: "5a68513f7e7353706e788781eff6e56bf00bb41b"},
       {:concurrent_limiter,
        git: "https://akkoma.dev/AkkomaGang/concurrent-limiter.git",
        ref: "a9e0b3d64574bdba761f429bb4fba0cf687b3338"},