fix conanws folder (conan-io#18352)

Author: memsharded

conan/api/subapi/workspace.py

@@ -25,10 +25,8 @@ def _find_ws_folder():
     path = Path(os.getcwd())
     while path.is_dir() and len(path.parts) > 1:  # finish at '/' or 'conanws/'
         if path.name == WORKSPACE_FOLDER:
-            if not (path / WORKSPACE_YML).is_file() and not (path / WORKSPACE_PY).is_file():
-                raise ConanException("Within the 'conanws/' folder, there should be at least one of "
-                                     f"these files: {WORKSPACE_YML} and/or {WORKSPACE_PY}")
-            return str(path)
+            if (path / WORKSPACE_YML).is_file() or (path / WORKSPACE_PY).is_file():
+                return str(path)
         if (path / WORKSPACE_YML).is_file() or (path / WORKSPACE_PY).is_file():
             return str(path)
         else:

test/integration/workspace/test_workspace.py

@@ -27,8 +27,7 @@ def test_workspace_root(self):
         c.save({"conanws/test.txt": ""})
         with c.chdir("conanws"):
             c.run("workspace root", assert_error=True)
-            assert ("ERROR: Within the 'conanws/' folder, there should be at least one of these "
-                    "files: conanws.yml and/or conanws.py") in c.out
+            assert "ERROR: No workspace defined, conanws.py file not found" in c.out
             c.save({"conanws.yml": ""})
             c.run("workspace root")
             assert c.current_folder in c.stdout