Update dependencies

[triskell]

Hi Alois! I upgraded the dependencies to make spaces compatible with freezed and freezed_annotation used in the device_preview package. I upgraded other packages too, to keep the project's dependencies up to date. I hope it will help.

[7flash]

Because every version of sleek_typography from git depends on freezed_annotation ^0.7.1 and spaces 0.5.0 depends on freezed_annotation ^0.13.0-nullsafety.0, sleek_typography from git is incompatible with spaces 0.5.0. And because no versions of spaces match >0.5.0 <0.6.0, sleek_typography from git is incompatible with spaces ^0.5.0. So, because fluneumora depends on both spaces ^0.5.0 and sleek_typography from git, version solving failed. pub get failed (1; So, because fluneumora depends on both spaces ^0.5.0 and sleek_typography from git, version solving failed.)

[triskell]

@7flash It seems you're having dependencies issues with sleek_typography. Maybe it would be interesting to propose a PR to update dependencies ?