fix: Use camera argument name in Forge2DGame

[spydon]

Description

Since the old camera now is completely removed, to be consistent with FlameGame the Forge2DGame should also name it's camera argument camera.

Fixes #3114

Checklist

• I have followed the Contributor Guide when preparing my PR.
• I have updated/added tests for ALL new/updated/fixed functionality.
• I have updated/added relevant documentation in docs and added dartdoc comments with ///.
• I have updated/added relevant examples in examples or docs.

Breaking Change?

• No, this PR is not a breaking change.

Related Issues

[ufrshubham]

LGTM! Now I'll have to re-record some parts of my upcoming video 🥲

[domesticmouse]

Any ideas on when this will hit production? My CI will catch it anyway, but it'd be nice to have the right thing in the published codelab for a lil while at least =)

[ufrshubham]

Any ideas on when this will hit production? My CI will catch it anyway, but it'd be nice to have the right thing in the published codelab for a lil while at least =)

This is not a breaking change right now. So even if it is released it shouldn't break anything for a while. Most probably users will just see a deprecation warning until it is completely removed.

[spydon]

Any ideas on when this will hit production? My CI will catch it anyway, but it'd be nice to have the right thing in the published codelab for a lil while at least =)

Just released flame_forge2d v0.18.0 :)
If you know anyone at Google to poke to get them to look at my design doc for how to do semi-automatic releases, this process would be a lot less cumbersome. 😄
dart-lang/pub-dev#7177 (comment)