Fix Nix builds: force use of pyproject, fix pynrfjprog dependency spec

Author: lschuermann

default.nix

@@ -79,6 +79,12 @@ in pkgs.python3Packages.buildPythonPackage rec {
     in elemAt (match pattern (readFile ./tockloader/_version.py)) 0;
   name = "${pname}-${version}";
 
+  pyproject = true;
+
+  nativeBuildInputs = with python3Packages; [
+    flit
+  ];
+
   propagatedBuildInputs = with python3Packages; [
     argcomplete
     colorama

pyproject.toml

@@ -16,7 +16,7 @@ dependencies = [
     "crcmod >= 1.7",
     "ecdsa >= 0.19.1",
     "pycryptodome >= 3.15.0",
-    "pynrfjprog == 10.19.0",
+    "pynrfjprog >= 10.19.0",
     "pyserial >= 3.0.1",
     "siphash >= 0.0.1",
     "six >= 1.9.0",