python-flask-babel: update to 4.0.0; add test.sh

Changes since 3.1.0:
- drop Python 3.7 support; add PyPy 3.9 compatibility
- replace deprecated locked_cached_property with cached_property

Signed-off-by: Alexandru Ardelean <alex@shruggie.ro>

lang/python/python-flask-babel/test.sh

@@ -0,0 +1,20 @@
+#!/bin/sh
+
+[ "$1" = python3-flask-babel ] || exit 0
+
+python3 - <<'EOF'
+from flask import Flask
+from flask_babel import Babel, gettext, lazy_gettext
+
+app = Flask(__name__)
+babel = Babel(app)
+
+with app.app_context():
+    result = gettext("Hello")
+    assert isinstance(result, str), "gettext should return a string"
+
+lazy = lazy_gettext("World")
+assert str(lazy) == "World", f"lazy_gettext failed: {lazy!r}"
+
+print("python3-flask-babel OK")
+EOF