Removes the second build.zig in the examples directory and incorporates it
into the main build.zig. This gives the zig build system the data needed to
know if the raylib library needs to be rebuilt when running any example.

* Update build.zig.zon for latest framework commit

* Update build.zig.zon with correct hash

* Update build.zig.zon with the 'really' correct hash

- Add xcode_frameworks when cross compiling for mac (ref:
https://github.com/hexops/mach/blob/main/build.zig)
- Add emsdk when cross compiling for wasm (ref:
https://github.com/floooh/sokol-zig/blob/master/build.zig)

Signed-off-by: Tomas Slusny <slusnucky@gmail.com>