Clarify Docker Python interpreter verification method

Draws a clearer distinction between verifying the interpreter in the container, vs on the host (handled in BaseCommand::verify_required_python), and system Python verification in verify_system_python

src/briefcase/platforms/linux/system.py

@@ -386,7 +386,7 @@ def clone_options(self, command):
         self.target_image = command.target_image
         self.extra_docker_build_args = command.extra_docker_build_args
 
-    def verify_python(self, app: AppConfig):
+    def verify_docker_python(self, app: AppConfig):
         """Verify that the version of Python being used to build the app in Docker is
         compatible with the version being used to run Briefcase.
 
@@ -591,7 +591,7 @@ def verify_app_tools(self, app: AppConfig):
             # Check the system Python on the target system to see if it is
             # compatible with Briefcase.
             if verify_python:
-                self.verify_python(app)
+                self.verify_docker_python(app)
         else:
             NativeAppContext.verify(tools=self.tools, app=app)
 

tests/platforms/linux/system/test_mixin__verify.py

@@ -80,7 +80,7 @@ def test_linux_docker(create_command, first_app_config, tmp_path, monkeypatch):
         "verify",
         mock_docker_app_context_verify,
     )
-    create_command.verify_python = MagicMock()
+    create_command.verify_docker_python = MagicMock()
 
     # Verify the tools
     create_command.verify_tools()
@@ -106,14 +106,14 @@ def test_linux_docker(create_command, first_app_config, tmp_path, monkeypatch):
     )
 
     # Python was also verified
-    create_command.verify_python.assert_called_once_with(first_app_config)
+    create_command.verify_docker_python.assert_called_once_with(first_app_config)
 
     # Reset the mock, then invoke verify_app_tools a second time.
-    create_command.verify_python.reset_mock()
+    create_command.verify_docker_python.reset_mock()
     create_command.verify_app_tools(app=first_app_config)
 
     # Python will *not* be verified a second time.
-    create_command.verify_python.assert_not_called()
+    create_command.verify_docker_python.assert_not_called()
 
 
 def test_non_linux_docker(create_command, first_app_config, tmp_path, monkeypatch):
@@ -159,7 +159,7 @@ def test_non_linux_docker(create_command, first_app_config, tmp_path, monkeypatc
         "verify",
         mock_docker_app_context_verify,
     )
-    create_command.verify_python = MagicMock()
+    create_command.verify_docker_python = MagicMock()
 
     # Verify the tools
     create_command.verify_tools()
@@ -185,11 +185,11 @@ def test_non_linux_docker(create_command, first_app_config, tmp_path, monkeypatc
     )
 
     # Python was also verified
-    create_command.verify_python.assert_called_once_with(first_app_config)
+    create_command.verify_docker_python.assert_called_once_with(first_app_config)
 
     # Reset the mock, then invoke verify_app_tools a second time.
-    create_command.verify_python.reset_mock()
+    create_command.verify_docker_python.reset_mock()
     create_command.verify_app_tools(app=first_app_config)
 
     # Python will *not* be verified a second time.
-    create_command.verify_python.assert_not_called()
+    create_command.verify_docker_python.assert_not_called()

tests/platforms/linux/system/test_mixin__verify_python.py

@@ -23,7 +23,7 @@ def test_match(create_command, first_app_config, capsys):
     )
 
     # Verify python for the app
-    create_command.verify_python(first_app_config)
+    create_command.verify_docker_python(first_app_config)
 
     # The docker container was interrogated for a Python version
     create_command.tools[
@@ -62,7 +62,7 @@ def test_mismatch(create_command, first_app_config, capsys):
     )
 
     # Verify python for the app
-    create_command.verify_python(first_app_config)
+    create_command.verify_docker_python(first_app_config)
 
     # The docker container was interrogated for a Python version
     create_command.tools[
@@ -107,7 +107,7 @@ def test_target_too_old(create_command, first_app_config):
         match=r"The system python3 version provided by somevendor:surprising "
         r"is 3\.7\.16; Briefcase requires a minimum Python3 version of 3\.9\.",
     ):
-        create_command.verify_python(first_app_config)
+        create_command.verify_docker_python(first_app_config)
 
     # The docker container was interrogated for a Python version
     create_command.tools[