Eliminate build warnings from the Scrap crate (#13383)

* Updated build.rs to tell RustC that dxgi, quartz and x11 are expected configurations.
Added lifetime annotations to various methods in common/aom.rs and common/vpxcodec.rs.
Updated common/vpx.rs to allow unused_imports in the generated bindings.
Updated dxgi/mag.rs to allow non_snake_case identifiers like "dwFilterMode".

* Added lifetime annotations to methods in common/hwcodec.rs and common/vram.rs.

* Switched syntax for the rustc-check-cfg directive emitted by build.rs in the scrap crate to use syntax compatible with Rust toolchain version 1.75. The double-colon syntax requires 1.77 or newer, but the older single-colon syntax works fine on newer versions for this directive.

* Update libs/scrap/build.rs

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Revert apparently-erroneous AI suggestion. It's usually pretty good, but not always right it seems. :-)

This reverts commit bf862b13f6.

* Removed redundant configuration directives from libs/scrap/build.rs.

---------

Co-authored-by: RustDesk <71636191+rustdesk@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

libs/scrap/src/dxgi/mag.rs

@@ -1,4 +1,6 @@
 // logic from webrtc -- https://github.com/shiguredo/libwebrtc/blob/main/modules/desktop_capture/win/screen_capturer_win_magnifier.cc
+#![allow(non_snake_case)]
+
 use lazy_static;
 use std::{
     ffi::CString,