Development: devcontainer fixes for Windows (#10843)

Development: devcontainer fixes for Windows (#10843)

* chore(devcontainer): drop read-only host .gitconfig bind mount

The bind mount prevented adjusting git config inside the dev container, and VS Code Dev Containers already copies the host .gitconfig automatically, making the mount unnecessary. This restores ability to manage git settings within the container.

* chore(gitignore): ignore .pnpm-store folder for pnpm package management

Add .pnpm-store/ to .gitignore to prevent local pnpm package store from being tracked by git when using the devcontainer.

* docs(development): clarify VS Code devcontainer setup steps for Windows

Add instructions, how to overcome some issues caused by using Windows as host system.