nftables: remove python patch

Replaced the patch with `--replace-fail` based on @quentinmit and
@Izorkin recommendation.

pkgs/os-specific/linux/nftables/fix-py-libnftables.patch

@@ -1,13 +0,0 @@
-diff --git a/py/src/nftables.py b/py/src/nftables.py
-index f1e43ade..9adcd1be 100644
---- a/py/src/nftables.py
-+++ b/py/src/nftables.py
-@@ -69,7 +69,7 @@ class Nftables:
- 
-     validator = None
- 
--    def __init__(self, sofile="libnftables.so.1"):
-+    def __init__(self, sofile="@out@/lib/libnftables.so.1"):
-         """Instantiate a new Nftables class object.
- 
-         Accepts a shared object file to open, by default standard search path

pkgs/os-specific/linux/nftables/python.nix

@@ -9,11 +9,9 @@ buildPythonPackage {
   inherit (nftables) version src;
   pyproject = true;
 
-  patches = [ ./fix-py-libnftables.patch ];
-
   postPatch = ''
     substituteInPlace "py/src/nftables.py" \
-      --subst-var-by "out" "${nftables}"
+      --replace-fail "libnftables.so.1" "${nftables}/lib/libnftables.so.1"
   '';
 
   setSourceRoot = "sourceRoot=$(echo */py)";