Fix ansible-test PATH handling.

changelogs/fragments/ansible-test-path-to-python.yml

@@ -0,0 +1,3 @@
+bugfixes:
+    - ansible-test no longer optimizes setting ``PATH`` by prepending the directory containing the selected Python interpreter when it is named ``python``.
+      This avoids unintentionally making other programs available on ``PATH``, including an already installed version of Ansible.

test/lib/ansible_test/_internal/util_common.py

@@ -168,11 +168,6 @@ def get_python_path(args, interpreter):
     :type interpreter: str
     :rtype: str
     """
-    # When the python interpreter is already named "python" its directory can simply be added to the path.
-    # Using another level of indirection is only required when the interpreter has a different name.
-    if os.path.basename(interpreter) == 'python':
-        return os.path.dirname(interpreter)
-
     python_path = PYTHON_PATHS.get(interpreter)
 
     if python_path: