Fix python unicode encoding problem when install gef in non-ascii locale

[fjh1997]

Description

To make python using UTF-8 when outputting to the pipe

Some users in Asian regions using non-ASCII languages may encounter issues when installing GEF with msys2 on Windows. The error message might be: "UnicodeEncodeError: 'gbk' codec can't encode character '\u21b3' in position 5137: illegal multibyte sequence." The reason is that Python is not using UTF-8 when outputting to the pipe, so the -x parameter needs to be added.

Make installation easier

• My code follows the code style of this project.
• My change includes a change to the documentation, if required.
• If my change adds new code, adequate tests have been added.
• I have read and agree to the CONTRIBUTING document.

[github-actions]

🤖 Coverage update for c8746dd 🟢

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[Grazfather]

Thank you!