[WIP] gdal

[Copilot]

Adding GDAL (Geospatial Data Abstraction Library) recipe for emscripten-forge

Plan:

• Explore repository structure and understand existing patterns
• Research GDAL dependencies and check availability in emscripten-forge
• Create GDAL recipe directory structure
• Create recipe.yaml with proper dependencies and configuration
• Create build.sh script using emcmake/emmake pattern
• Create overwriteProp.cmake if needed for cross-compilation
• Refine recipe based on patterns from similar packages
• Test the recipe build
• Add appropriate tests for GDAL installation

Updated GDAL recipe with:

• Changed to GDAL 3.8.5 (more stable than 3.10.0)
• Simplified CMake configuration to avoid overly complex dependency specification
• Removed explicit library path settings to let CMake find dependencies automatically
• Kept essential WebAssembly optimizations (disabled CURL, OpenSSL, apps, bindings)

GDAL is a crucial geospatial library that will enable many Python packages like rasterio, fiona, and others to work in the emscripten environment.

Fixes #2799.

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