`assertion failed: data.is::<T>()` on command buffer drop

[Wumpf]

Description
Intermittent assertion when dropping a command buffer when using webgl (not webgpu as in otherwise related #3710)
Haven't isolated yet which circumstances are necessary to trigger this:

panicked at 'assertion failed: data.is::<T>()', /Users/andreas/.cargo/registry/src/gitproxy.zycloud.tk-1ecc6299db9ec823/wgpu-0.16.0/src/context.rs:1045:5

Stack:

getImports/imports.wbg.__wbg_new_abda76e883ba8a5f/<@http://127.0.0.1:9090/re_viewer.js:422:21
logError@http://127.0.0.1:9090/re_viewer.js:241:18
getImports/imports.wbg.__wbg_new_abda76e883ba8a5f@http://127.0.0.1:9090/re_viewer.js:421:66
console_error_panic_hook::hook::h7085f0f35ae12a82@http://127.0.0.1:9090/re_viewer.js line 383 > WebAssembly.instantiate:wasm-function[5590]:0x772074
core::ops::function::Fn::call::h4a4c198ad3cbb4af@http://127.0.0.1:9090/re_viewer.js line 383 > WebAssembly.instantiate:wasm-function[20779]:0xa34346
eframe::web::backend::start_web::{{closure}}::{{closure}}::h2be874fa9b88f1af@http://127.0.0.1:9090/re_viewer.js line 383 > WebAssembly.instantiate:wasm-function[11730]:0x98572b
std::panicking::rust_panic_with_hook::hbafe3e603d331223@http://127.0.0.1:9090/re_viewer.js line 383 > WebAssembly.instantiate:wasm-function[11784]:0x98856d
std::panicking::begin_panic_handler::{{closure}}::h8ab6ee68d5b4c391@http://127.0.0.1:9090/re_viewer.js line 383 > WebAssembly.instantiate:wasm-function[12896]:0x9bd960
std::sys_common::backtrace::__rust_end_short_backtrace::h008f69666d134159@http://127.0.0.1:9090/re_viewer.js line 383 > WebAssembly.instantiate:wasm-function[16919]:0xa1fe05
rust_begin_unwind@http://127.0.0.1:9090/re_viewer.js line 383 > WebAssembly.instantiate:wasm-function[15130]:0xa028b6
core::panicking::panic_fmt::h1d17fc068f528130@http://127.0.0.1:9090/re_viewer.js line 383 > WebAssembly.instantiate:wasm-function[16212]:0xa166e0
core::panicking::panic::h27b5eefa3e4ff738@http://127.0.0.1:9090/re_viewer.js line 383 > WebAssembly.instantiate:wasm-function[15333]:0xa06eb8
<T as wgpu::context::DynContext>::command_buffer_drop::ha1744d4f4947ce60@http://127.0.0.1:9090/re_viewer.js line 383 > WebAssembly.instantiate:wasm-function[14681]:0x9f7a2b
<wgpu::CommandBuffer as core::ops::drop::Drop>::drop::ha2e55b23d296c66c@http://127.0.0.1:9090/re_viewer.js line 383 > WebAssembly.instantiate:wasm-function[12229]:0x99f2a2

Platform
Firefox, webgl backend

[Wumpf]

Minimal repro for all platforms!

                let encoder =
                    device.create_command_encoder(&wgpu::CommandEncoderDescriptor { label: None });
                drop(encoder.finish());

I have a fix ready. PR incoming