fix: update python to python3 in myph.sh

[wuwentao]

PR Description

mypy.....................................................................Failed
- hook id: mypy
- exit code: 127

scripts/mypy.sh: line 7: python: command not found

Reason & Detail

Related issue

fix #X

[chemelli74]

Again something strange, python should be a symlink to the latest python available in the system

[chemelli74]

After #170 , is that still needed ?

[wuwentao]

Again something strange, python should be a symlink to the latest python available in the system

just for discussion:
most of the os don't have python symlink to python3, for example: ubuntu/debian/macos
as default python is python2 in old os and only use python3.

[chemelli74]

Again something strange, python should be a symlink to the latest python available in the system

just for discussion: most of the os don't have python symlink to python3, for example: ubuntu/debian/macos as default python is python2 in old os and only use python3.

The correct way is sudo apt install python-is-python3 - it effectively does a symlink, but it also keeps pace with future updates; so if your ubuntu distribution moves to say Python 3.9, the manual symlink will no longer work, but the package makes sure it is still valid.