🪚 Use pnpm instead of yarn

[janjakubnanista]

In this PR

All the changes required to make pnpm work. In order to install pnpm on your machine, you can:

# Install using npm
npm i -g pnpm

# Install using corepack
corepack enable

• Added missing dependencies
• Changed READMEs
• Updated Dockerfile, ignored bunch of files we don't need in the docker build
• Updated github actions
• Updated dependency versions
• Fixed minor build issues

If you think this PR is too big, I can split off the dependency fixes (mostly missing peer & dev dependencies), lmk