clightning: fix Python packages

Patching `pyln-proto` to use cryptography 38 lets
us avoid adding many older Python pkg versions.

The backwards incompatible changes from cryptography 36 to 38
only include the removal of deprecated fns that pyln-proto
doesn't use.
See string "BACKWARDS INCOMPATIBLE" in
https://cryptography.io/en/latest/changelog/

pkgs/clightning-plugins/default.nix

@@ -31,7 +31,7 @@ let
       description = "Lightning node exporter for the prometheus timeseries server";
       extraPkgs = [ prometheus_client ];
       patchRequirements =
-        "--replace prometheus-client==0.6.0 prometheus-client==0.13.1"
+        "--replace prometheus-client==0.6.0 prometheus-client==0.15.0"
         + " --replace pyln-client~=0.9.3 pyln-client~=22.11rc1";
     };
     rebalance = {

pkgs/python-packages/pyln-proto/default.nix

@@ -27,4 +27,8 @@ buildPythonPackage rec {
   checkInputs = [ pytestCheckHook ];
 
   postUnpack = "sourceRoot=$sourceRoot/contrib/pyln-proto";
+
+  postPatch = ''
+    sed -i 's|cryptography = "^36.0.1"|cryptography = "^38.0.0"|' pyproject.toml
+  '';
 }