build: split APKs by ABI to optimize size

[Integral-Tech]

This commit splits APKs by ABI (arm64-v8a, armeabi-v7a & x86_64) to optimize APK size.

Closes: #1026

Thank you so much for your contribution to FluffyChat ❤️❤️❤️

Please make sure that your Pull Request meet the following acceptance criteria:

• [x] Code formatting and import sorting has been done with dart format lib/ test/ and dart run import_sorter:main --no-comments
• [x] The commit message uses the format of Conventional Commits
• [x] The commit message describes what has been changed, why it has been changed and how it has been changed
• [x] Every new feature or change of the design/GUI is linked to an approved design proposal in an issue
• [x] Every new feature in the app or the build system has a strategy how this will be tested and maintained from now on for every release, e.g. a volunteer who takes over maintainership

Pull Request has been tested on:

• [ ] Android
• [ ] iOS
• [ ] Browser (Chromium based)
• [ ] Browser (Firefox based)
• [ ] Browser (WebKit based)
• [ ] Desktop Linux
• [ ] Desktop Windows
• [ ] Desktop macOS

[Integral-Tech]

@krille-chan Could you please approve the workflows?

[linsui]

For F-Droid users the client select the apk for them. For GitHub users you can publish the universal apk only.

[Integral-Tech]

For F-Droid users the client select the apk for them. For GitHub users you can publish the universal apk only.

@krille-chan Would you like to do that?

[linsui]

@krille-chan We can also only do this on F-Droid side if it works for you. The version code will be different from your apks but that won't cause any problem.

[Integral-Tech]

@krille-chan We can also only do this on F-Droid side if it works for you. The version code will be different from your apks but that won't cause any problem.

@krille-chan @linsui Resolved :)

[Integral-Tech]

@krille-chan Flutter 3.35.3 has been released which fixes the version code issue (https://github.com/flutter/flutter/issues/173917) Could you please update Flutter to 3.35.3 and approve this pull request?

[Integral-Tech]

@krille-chan Building a universal APK is still supported :) Would you like to publish the universal APK only in GitHub Release, or publish both split APKs and the universal APK?