Log Message:
devel/gitui: update to 0.21.0

Added
    stack popups (#846)
    file history log [@cruessler] (#381)
    termux support on andriod [@PeroSar] (#1139)
    use GIT_DIR and GIT_WORK_DIR from environment if set (#1191)
    new FAQs page
    mention macports in install section [@fs111](#1237)
    support copy to clipboard on wayland [@JayceFayne] (#397)

Fixed
    opening tags list without remotes (#1111)
    tabs indentation in blame [@fersilva16] (#1117)
    switch focus to index after staging last file (#1169)
    fix stashlist multi marking not updated after dropping (#1207)
    exact matches have a higher priority and are placed to the top of the list
     when fuzzily finding files (#1183)

Changed
    minimum supported rust version bumped to 1.60 (#1279)