install.sh cleanup asks for confirmation for every file

[EddyLuten]

When running the install.sh script during the final deletion steps:

rm -r raygui
rm -r raylib

Confirmation is needed for every single file:

rm: remove write-protected regular file 'raygui/.git/objects/pack/pack-c928635f2bd28835e7ff73890fec18b8f1b0d2b5.pack'? y
rm: remove write-protected regular file 'raygui/.git/objects/pack/pack-c928635f2bd28835e7ff73890fec18b8f1b0d2b5.idx'? y
rm: remove write-protected regular file 'raylib/build/raylib/CMakeFiles/raylib.dir/compiler_depend.internal'? y
rm: remove write-protected regular file 'raylib/build/raylib/CMakeFiles/raylib.dir/compiler_depend.make'? y
rm: remove write-protected regular file 'raylib/build/raylib/external/glfw/src/CMakeFiles/glfw.dir/compiler_depend.internal'? y
rm: remove write-protected regular file 'raylib/build/raylib/external/glfw/src/CMakeFiles/glfw.dir/compiler_depend.make'? y
rm: remove write-protected regular file 'raylib/build/install_manifest.txt'? y
rm: remove write-protected regular file 'raylib/build/examples/CMakeFiles/raylib_opengl_interop.dir/compiler_depend.internal'? y
rm: remove write-protected regular file 'raylib/build/examples/CMakeFiles/raylib_opengl_interop.dir/compiler_depend.make'? y
rm: remove write-protected regular file 'raylib/build/examples/CMakeFiles/shapes_lines_bezier.dir/compiler_depend.internal'? y
rm: remove write-protected regular file 'raylib/build/examples/CMakeFiles/shapes_lines_bezier.dir/compiler_depend.make'? y
rm: remove write-protected regular file 'raylib/build/examples/CMakeFiles/core_2d_camera_platformer.dir/compiler_depend.internal'? y

etc.

Adding the -f flag would stop the prompting for each file.

I'll open a PR for this change and link it here.

PS: It would probably also be a good idea to add a small cleanup script to remove symlinks and build artifacts if install.sh is run again.