Replace Yarn with pnpm for build reliability

[samshara]

Currently, the build process often fails when using Yarn due to the following error:

Error: Extracting tar content of undefined failed

This issue causes builds to be unreliable and slows down development. After researching alternative package managers, pnpm has been identified as a more reliable and efficient option for our workflow.

Proposed Solution

1. Replace yarn with pnpm for managing dependencies and the build process.
2. Update project documentation to reflect the new setup.
3. Ensure CI/CD pipelines are updated to use pnpm instead of Yarn.

Benefits

• Improved build reliability.
• Potential for reduced build times.

[tnagorra]

We should be able to use pnpm import to import the lock file to pnpm. Also, we can remove post-install package (it's already available on npm and pnpm)