python-ruamel-yaml: update to 0.19.1

- Bump version 0.18.16 -> 0.19.1
- Add PYPI_SOURCE_NAME:=ruamel_yaml
- Add PKG_BUILD_BUILDIR, because folder is ruamel.yaml
- Add test.sh

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

lang/python/python-ruamel-yaml/test.sh

@@ -0,0 +1,30 @@
+#!/bin/sh
+
+[ "$1" = python3-ruamel-yaml ] || exit 0
+
+python3 - << 'EOF'
+from ruamel.yaml import YAML
+from io import StringIO
+
+yaml = YAML()
+
+# Test basic load/dump
+data = yaml.load("key: value\nlist:\n  - a\n  - b\n")
+assert data["key"] == "value"
+assert data["list"] == ["a", "b"]
+
+out = StringIO()
+yaml.dump({"x": 1}, out)
+assert "x: 1" in out.getvalue()
+
+# Test roundtrip comment preservation (key ruamel.yaml feature)
+doc = "# header\nname: test  # inline\n"
+data2 = yaml.load(doc)
+assert data2["name"] == "test"
+buf = StringIO()
+yaml.dump(data2, buf)
+assert "# header" in buf.getvalue()
+assert "# inline" in buf.getvalue()
+
+print("python3-ruamel-yaml OK")
+EOF