devel/rust-cbindgen: temporarily revert r558794

mail/thunderbird and www/firefox-esr failed with

In file included from Unified_cpp_dom_webgpu1.cpp:110:
dom/webgpu/ipc/WebGPUParent.cpp:426:29: error: no member named '_0' in 'mozilla::webgpu::ffi::WGPUBufferBinding'

bgb.resource.buffer._0.buffer = entry.mValue;
~~~~~~~~~~~~~~~~~~~ ^

dom/webgpu/ipc/WebGPUParent.cpp:427:29: error: no member named '_0' in 'mozilla::webgpu::ffi::WGPUBufferBinding'

bgb.resource.buffer._0.offset = entry.mBufferOffset;
~~~~~~~~~~~~~~~~~~~ ^

dom/webgpu/ipc/WebGPUParent.cpp:428:29: error: no member named '_0' in 'mozilla::webgpu::ffi::WGPUBufferBinding'

bgb.resource.buffer._0.size = entry.mBufferSize;
~~~~~~~~~~~~~~~~~~~ ^

dom/webgpu/ipc/WebGPUParent.cpp:432:34: error: member reference base type 'mozilla::webgpu::ffi::WGPUTextureViewId' (aka 'unsigned long long') is not a structure or union

bgb.resource.texture_view._0 = entry.mValue;
~~~~~~~~~~~~~~~~~~~~~~~~~^~~

Don't force downgrade via PORTEPOCH as www/firefox is fine and I plan
to re-land soon.

Reported by: pkg-fallout, leres