chore: rewrite extract-requirements to python

Using python ast to guess requirements in the setup.py file.

tools/extract_requirements.py

@@ -0,0 +1,57 @@
+#!/usr/bin/env python3
+
+# Extract the dependencies from the setup.py files
+# and save the result to requirements.txt.
+#
+# You can filter any extra require by adding the name as argument.
+#
+# Examples:
+#   tools/extract_requirements.py
+#   tools/extract_requirements.py dev
+
+
+import ast
+from glob import glob
+from pathlib import Path
+from sys import argv
+
+
+class RemoveJoinedStr(ast.NodeTransformer):
+    def visit_JoinedStr(self, _node):  # pylint: disable=invalid-name
+        pass
+
+
+for setup in glob("*/setup.py"):
+    setup_path = Path(setup)
+    requirements_path = setup_path.parent / "requirements.txt"
+
+    lines = [
+        "# Please do not edit this file, edit the setup.py file!",
+        "# This file is auto-generated by tools/extract_requirements.py.",
+    ]
+
+    requires = []
+
+    for node in ast.walk(ast.parse(setup_path.read_text(encoding="utf-8"))):
+        if (
+            isinstance(node, ast.Expr)
+            and isinstance(node.value, ast.Call)
+            and isinstance(node.value.func, ast.Name)
+            and node.value.func.id == "setup"
+        ):
+
+            for keyword in node.value.keywords:
+                if keyword.arg == "install_requires":
+                    requires.extend(ast.literal_eval(keyword.value))
+
+                if keyword.arg == "extras_require":
+                    extras = ast.literal_eval(RemoveJoinedStr().visit(keyword.value))
+
+                    for key, values in extras.items():
+                        if key in argv:
+                            continue
+                        requires.extend(values)
+
+    lines.extend(sorted(requires))
+
+    requirements_path.write_text("\n".join(lines) + "\n", encoding="utf-8")