Add patch to remove .cargo/config.toml to fix aarch64 nix builds

Using the flake on aarch4-linux in nix leads to an error `error: linker
'aarch64-linux-gnu-gcc' not found` which is apparently fixed by deleting
the `.cargo/config.toml` according to this nixos issue / PR
NixOS/nixpkgs#209697

flake.nix

@@ -54,6 +54,12 @@
           # Common arguments can be set here to avoid repeating them later
           commonArgs = {
             inherit src;
+
+            patches = [
+              # the presence of .cargo/config.toml apparently
+              # breaks nix builds on aarch64-linux
+              ./nix/patches/remove-cargo-config-toml.patch
+            ];
             strictDeps = true;
             nativeBuildInputs = [
               pkgs.protobuf

nix/patches/remove-cargo-config-toml.patch

@@ -0,0 +1,30 @@
+:100644 000000 a55a502bb 000000000 D	.cargo/config.toml
+
+diff --git a/.cargo/config.toml b/.cargo/config.toml
+deleted file mode 100644
+index a55a502bb..000000000
+--- a/.cargo/config.toml
++++ /dev/null
+@@ -1,22 +0,0 @@
+-[target.x86_64-unknown-linux-gnu]
+-rustflags = ["-C", "target-feature=+sse2,+ssse3,+sse4.1,+sse4.2"]
+-
+-[target.x86_64-unknown-linux-musl]
+-rustflags = ["-C", "target-feature=+sse2,+ssse3,+sse4.1,+sse4.2"]
+-
+-[target.aarch64-unknown-linux-gnu]
+-linker = "aarch64-linux-gnu-gcc"
+-rustflags = ["-C", "target-feature=+neon"]
+-
+-[target.aarch64-unknown-linux-musl]
+-linker = "aarch64-linux-gnu-gcc"
+-rustflags = ["-C", "target-feature=+neon"]
+-
+-[target.aarch64-apple-darwin]
+-rustflags = ["-C", "target-feature=+neon"]
+-
+-[target.x86_64-apple-darwin]
+-rustflags = ["-C", "target-feature=+sse2,+ssse3,+sse4.1,+sse4.2"]
+-
+-[target.x86_64-pc-windows-msvc]
+-rustflags = ["-C", "target-feature=+sse2,+ssse3,+sse4.1,+sse4.2"]