Fix: "The build mesh uniforms pipeline wasn't ready” warning now fires only once

[kfc35]

Objective

• Fixes 0.18.0-rc.2 WASM "The build mesh uniforms pipeline wasn't ready" log spam #22358

Solution

• Use warn_once for the log message (and add bevy_log as a dependency for bevy_pbr)

Testing

I added main.rs in the reproduction repo https://github.com/logankaser/bevy-uniforms-pipeline-repro/blob/main/src/main.rs as an example file in the main bevy repo and ran it with bevy run --example repro --features=bevy_camera,bevy_core_pipeline,bevy_log,bevy_pbr,bevy_render,bevy_window,bevy_winit,webgpu web --open.

I opened up the app in Chrome and verified in the console log that the warning only fires once

screenshots of console logs

In google chrome beforehand, you see the spam in the console:

After the change, it just warns once:

[alice-i-cecile]

We have a dedicated warn_once! macro for exactly this :)

[kfc35]

We have a dedicated warn_once! macro for exactly this :)

Hah I had that initially but then changed it to once!(warn()) because I had to add bevy_log as a dependency and did not now how that would be received!

I'll change it back to warn_once!