pinnwand: Relax sqlalchemy constraint

Package test and integration tests are passing and I reported that
success story upstream.

pkgs/servers/pinnwand/default.nix

@@ -21,6 +21,11 @@ with python3.pkgs; buildPythonApplication rec {
     poetry-core
   ];
 
+  postPatch = ''
+    substituteInPlace pyproject.toml \
+      --replace 'sqlalchemy = "^1.4"' 'sqlalchemy = "*"'
+  '';
+
   propagatedBuildInputs = [
     click
     docutils