feat(users/edef/weave): use FxHashSet and dedupe early

Deduping early saves a fair bit of memory, but the extra hashing is
costly.

We switch to FxHash, since we don't need a DoS-proof hash, but we do
need it to be *fast*.

Change-Id: Ic6b7010874c417862baa9b882593208c8dd1d5e6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/12648
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI

users/edef/weave/Cargo.lock

@@ -1556,6 +1556,12 @@ version = "0.1.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "719b953e2095829ee67db738b3bfa9fa368c94900df327b3f07fe6e794d2fe1f"
 
+[[package]]
+name = "rustc-hash"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "583034fd73374156e66797ed8e5b0d5690409c9226b22d87cb7f19821c05d152"
+
 [[package]]
 name = "rustc_version"
 version = "0.4.1"
@@ -2027,6 +2033,7 @@ dependencies = [
  "nix-compat",
  "polars",
  "rayon",
+ "rustc-hash",
  "safer_owning_ref",
 ]