package/python-txtorcon: drop python2 support

Txtorcon is built on top of twisted, which is python3 only since commit
f1db1922e460d4f (package/python-twisted: Needs python 3), so propagate the
python3 dependency.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/python-txtorcon/Config.in

@@ -1,6 +1,7 @@
 config BR2_PACKAGE_PYTHON_TXTORCON
 	bool "python-txtorcon"
 	depends on BR2_INSTALL_LIBSTDCPP # python-pyopenssl, python-service-identity
+	depends on BR2_PACKAGE_PYTHON3 # python-twisted
 	select BR2_PACKAGE_PYTHON_AUTOMAT # runtime
 	select BR2_PACKAGE_PYTHON_IDNA # runtime
 	select BR2_PACKAGE_PYTHON_INCREMENTAL # runtime

support/testing/tests/package/test_python_txtorcon.py

@@ -1,17 +1,6 @@
 from tests.package.test_python import TestPythonPackageBase
 
 
-class TestPythonPy2Txtorcon(TestPythonPackageBase):
-    __test__ = True
-    config = TestPythonPackageBase.config + \
-        """
-        BR2_PACKAGE_PYTHON=y
-        BR2_PACKAGE_PYTHON_TXTORCON=y
-        """
-    sample_scripts = ["tests/package/sample_python_txtorcon.py"]
-    timeout = 30
-
-
 class TestPythonPy3Txtorcon(TestPythonPackageBase):
     __test__ = True
     config = TestPythonPackageBase.config + \