6.4.0: Merge pull request #15 from spatial-model-editor/6_4

qt -> 6.4.0

6.3.1-zlib: Merge pull request #13 from spatial-model-editor/libz

add static libz library

6.3.1-msvc

Revert removal of msvc & mingw 32-bit builds

Qt -> 6.3.1

- ubuntu 18.04 -> 20.04
    - ubuntu 18.04 runners are being removed from GHA
- also remove unused msvc and mingw 32-bit builds

6.3.0-msys2-gcc12

msys2 upgraded mingw gcc to 12

Qt -> 6.3.0

also update build config:

- ubuntu: clang 13 -> 14
- mac: os 10.15 -> 11
- windows: os 2019 -> 2022
- update actions versions
- update pre-commit

6.2.3

update qt version in readme

6.2.0-clang

revert to 6.2.0 again due to msys2 git checkout issue (see #6)

6.2.0

Qt -> 6.2.0

6.1.3

remove bundled libss option (removed from qt 6.1.3 on linux)