editors/elementary-code: Update to 8.1.2

While here:

• Fix LICENSE
• Switch to USES=gettext-tools

Author's Note: spell plugin has been disabled. Because it depends of
gtkspell3, which seems unmaintained (no update since 2018).

Changelog:

• https://github.com/elementary/code/releases/tag/8.0.0
• https://github.com/elementary/code/releases/tag/8.1.0
• https://github.com/elementary/code/releases/tag/8.1.1
• https://github.com/elementary/code/releases/tag/8.1.2

PR: 290018
Reported by: Olivier Duchateau <duchateau.olivier@gmail.com>
Approved by: Miguel Gocobachi <miguel@gocobachi.dev>