Optimize Dockerfile layers and improve readability

[Madmaxs2]

Changes in docker/deployer/Dockerfile:

Before:

After:

Improvements:

1. Reduced Docker Layers

   • Combined multiple ENV commands into a single one
   • Fewer layers result in smaller image size and better performance

2. Better Caching

   • Using --mount=type=cache for efficient caching of downloaded files
   • Faster subsequent builds by reusing cached content

3. Atomic Operations

   • Related commands are grouped together
   • Ensures all installations either succeed completely or fail entirely
   • Prevents partial/incomplete states

4. Enhanced Readability

   • Logically grouped PATH configurations
   • Cleaner and more maintainable code structure

These optimizations improve build efficiency, reduce image size, and enhance code maintainability without changing any functionality.