* gh-118673: Remove shebang and executable bits from stdlib modules.
* Removed shebangs and exe bits on turtledemo scripts.
The setting was inappropriate for '__main__' and inconsistent across the other modules. The scripts can still be executed directly by invoking with the desired interpreter.
requires them. Disable executable bits and shebang lines in test and
benchmark files in order to prevent using a random system python, and in
source files of modules which don't provide command line interface. Fixed
shebang line to use python3 executable in the unittestgui script.