pythonPackages.asyncpg: fix build on older Python, bump minimum Python version (#294645)

pkgs/development/python-modules/asyncpg/default.nix

@@ -1,6 +1,7 @@
 { lib
 , fetchPypi
 , buildPythonPackage
+, async-timeout
 , uvloop
 , postgresql
 , pythonOlder
@@ -13,7 +14,7 @@ buildPythonPackage rec {
   version = "0.29.0";
   format = "setuptools";
 
-  disabled = pythonOlder "3.7";
+  disabled = pythonOlder "3.8";
 
   src = fetchPypi {
     inherit pname version;
@@ -23,6 +24,12 @@ buildPythonPackage rec {
   # sandboxing issues on aarch64-darwin, see https://github.com/NixOS/nixpkgs/issues/198495
   doCheck = postgresql.doCheck;
 
+  # required for compatibility with Python versions older than 3.11
+  # see https://github.com/MagicStack/asyncpg/blob/v0.29.0/asyncpg/_asyncio_compat.py#L13
+  propagatedBuildInputs = lib.optionals (pythonOlder "3.11") [
+    async-timeout
+  ];
+
   nativeCheckInputs = [
     uvloop
     postgresql