Update bindgen to 0.69.1

[CGMossa]

This should have absolutely no influence on bindings.

I saw a reaction at work, but that's because llvm 17 apparently snaps more comments in the bindings.
Now that I'm at home, this difference is not present.

But then now we can upgrade this in peace.

Also added -Wno-ignored-attributes because when you run this with

cargo clippy --features use-bindgen -vv

you see a warning

[libR-sys 0.6.0] clang diag: C:/rtools43/x86_64-w64-mingw32.static.posix/include\stdio.h:169:18: warning: '__format__' attribute argument not supported: gnu_scanf [-Wignored-attributes]

which we don't really care about, as we are creating bindings and not compiling this.

[CGMossa]

/bindings

[CGMossa]

/bindings

[CGMossa]

The call to /bindings doesn't work on this. I think GitHub CI fails here.

[yutannihilation]

I think GitHub CI fails here.

In case you don't notice, you can check the CI run here.

https://github.com/extendr/libR-sys/actions

[CGMossa]

/bindings

[CGMossa]

Dear @yutannihilation, I'd love it if you could take a final look at this, and merge when/if you find it done.

This was supposed to be a minor PR, but I knew there is always something coming up, and it is good these got addressed by you in #195.

These bindings also include the new OBJSXP value mentioned in extendr/extendr#664.

[yutannihilation]

Looks good.