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

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

[github-actions[bot]]

🤖 Coverage update for c8746ddb34a18bcea02f11685ca9b0a0d6f58a7f 🟢

	Old	New
Commit	89079354ae80f8b7f43f2c04d70d5a741c927da9	c8746ddb34a18bcea02f11685ca9b0a0d6f58a7f
Score	71.6267%	71.6267% (0)

[Grazfather]

Thank you!