[3.x] CI: Update Linux runners to Ubuntu 24.04, but keep 22.04 for Linux builds

[akien-mga]

Pin clang-format to version 16¹, and black to 24.10.0.

Mono needs to be reinstalled manually as they removed it in Ubuntu 24.04 images. (Still using the "focal" version, i.e. Ubuntu 20.04, as Mono upstream also no longer provides new versions for Ubuntu.)
In the end we keep Ubuntu 22.04 for the Linux and Server builds for portability, so Mono is still provided.

Footnotes

1. Could go higher, GH provides 16, 17, and 18 (default) in its Ubuntu 24.04 runner, but at least locally my clang-format 19 implies a bunch of changes and since I want to cherry-pick this to old 3.x branches, where I don't want to bother reformatting code, I'm sticking to something close to the previous 15. ↩

[akien-mga]

This was needed to workaround a GCC false positive:

 scene/2d/tile_map.cpp: In member function 'void TileMap::_set_tile_data(const PoolVector<int>&)':
Error: scene/2d/tile_map.cpp:1273:34: error: writing 1 byte into a region of size 0 [-Werror=stringop-overflow=]
 1273 |                         local[j] = ptr[j];
      |                         ~~~~~~~~~^~~~~~~~
scene/2d/tile_map.cpp:1271:25: note: at offset 12 into destination object 'local' of size 12
 1271 |                 uint8_t local[12];
      |                         ^~~~~

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104789

[Repiteo]

Will current CI be updated to 24.04 as well, or is this just for 3.x? In either case, what necessitates the version bump?

[akien-mga]

Will current CI be updated to 24.04 as well, or is this just for 3.x? In either case, what necessitates the version bump?

We should update 4.x branches too.

The motivation is to be ready for the future removal of GH's ubuntu:20.04 runner, which from experience should happen soon after making the N+2 LTS the default, which is happening now: https://github.blog/changelog/2024-11-05-notice-of-breaking-changes-for-github-actions/

[Repiteo]

We should update 4.x branches too.

Roger that

• CI: Update Linux runners to Ubuntu 24.04 #98898

[akien-mga]

I restored the Linux and Server builds to use Ubuntu 22.04 for portability. This also means Mono is still present in the image from GHA and doesn't need to be installed manually.

For when we'd eventually move those to Ubuntu 24.04, here's how to install Mono too:

# Mono, no longer provided in Ubuntu 24.04 images.
# https://github.com/actions/runner-images/blob/ae99c16b0cf27c0cca7ef0b08e7bcf13c33f6cfa/images/ubuntu/scripts/build/install-mono.sh
REPO_URL="https://download.mono-project.com/repo/ubuntu"
GPG_KEY="/usr/share/keyrings/mono-official-stable.gpg"
REPO_PATH="/etc/apt/sources.list.d/mono-official-stable.list"
curl -fsSL https://download.mono-project.com/repo/xamarin.gpg | sudo gpg --dearmor -o $GPG_KEY
echo "deb [signed-by=$GPG_KEY] $REPO_URL stable-focal main" | sudo tee $REPO_PATH
sudo apt-get install --no-install-recommends apt-transport-https mono-complete nuget

[akien-mga]

Finally got this working!

[lawnjelly]

Will leave for you to merge. 👍