fix: remove yarn add for playwright packages

[anastasialanz]

We had this problem earlier where the playwright image updates and we get an error. When running yarn add, Docker wasn't getting the ARG playwright_version so we need to redeclare it after the first FROM.

An ARG declared before a FROM is outside of a build stage, so it can't be used in any instruction after a FROM. To use the default value of an ARG declared before the first FROM use an ARG instruction without a value inside of a build stage

https://docs.docker.com/reference/dockerfile/#understand-how-arg-and-from-interact

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