fix: add extra dependencies for webgl and il2cpp

[mob-sakai]

Changes

• Fix Building for il2cpp StandaloneLinux64 and webgl fails with 'Could not find valid clang executable at clang' #53
• Add dependencies for webgl and linux-il2cpp
  • python
  • build-essential
  • clang

Checklist

• Read the contribution guide and accept the code of conduct
• Readme (updated or not needed)

Versions and modules to be fixed

Tested with #60 (in my repo)

version	WebGL	IL2CPP
2018.3.x	✅	✅
2018.4.x	✅	✅
2019.1.x	✅ (With #59)	✅
2019.2.x	✅	✅
2019.3.x	✅	❌
2019.4.x	✅	✅
2020.1.x	✅	✅
2020.2.x	✅	✅
2021.1.x	✅	❌

[webbertakken]

Nice work @mob-sakai

How much size does this add to the image without install recommends?

If it's relatively little we might add it to the base image as discussed in #53

[mob-sakai]

@webbertakken
About 340MB.

REPOSITORY   TAG       IMAGE ID       CREATED              SIZE
editor       after     bf3c52bbd759   1 second ago         6.38GB
editor       before    e0a43d920df0   About a minute ago   6.04GB

Test:

FROM unityci/editor:2019.4.18f1-webgl-0

RUN apt-get -q update \
  && apt-get -q install -y --no-install-recommends --allow-downgrades \
    python \
    build-essential \
    clang \
  && apt-get clean \
  && rm -rf /var/lib/apt/lists/*

[webbertakken]

Nice work!

[webbertakken]

@mob-sakai Do you think this fix is applicable for game-ci/unity-builder#143 (comment) (android il2cpp and ios-il2cpp)?

[mob-sakai]

@webbertakken
Maybe.
I'll test it later.

[mob-sakai]

@webbertakken
In my tests, android-il2cpp and ios-il2cpp built the project successfully with main branch.
No additional fixes are required

NOTE: In 2018.3 or later, ios uses il2cpp script backend by default for building.

[mob-sakai]

@webbertakken
Should I add android-il2cpp to test workflow?

Like this commit: mob-sakai@7d5be32
Test results: https://github.com/mob-sakai/docker/runs/1746625453

[webbertakken]

I think @davidmfinol is more qualified to answer this. It seems that there are cases (maybe all) where Android IL2CPP already works as well.