Expose wgpu profiling scopes to puffin (#4581)

### What

![image](https://github.com/rerun-io/rerun/assets/1148717/d29b5cff-162a-45d6-9e60-fd8c465d0e85)

(only CPU profile scopes though, nothing from GPU)

### Checklist
* [x] I have read and agree to [Contributor
Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)
* [x] I've included a screenshot or gif (if applicable)
* [x] I have tested the web demo (if applicable):
* Using newly built examples:
[app.rerun.io](https://app.rerun.io/pr/4581/index.html)
* Using examples from latest `main` build:
[app.rerun.io](https://app.rerun.io/pr/4581/index.html?manifest_url=https://app.rerun.io/version/main/examples_manifest.json)
* Using full set of examples from `nightly` build:
[app.rerun.io](https://app.rerun.io/pr/4581/index.html?manifest_url=https://app.rerun.io/version/nightly/examples_manifest.json)
* [x] The PR title and labels are set such as to maximize their
usefulness for the next release's CHANGELOG

- [PR Build Summary](https://build.rerun.io/pr/4581)
- [Docs
preview](https://rerun.io/preview/3e4a767719690309d769f1a3b5974f8bd7c693bd/docs)
<!--DOCS-PREVIEW-->
- [Examples
preview](https://rerun.io/preview/3e4a767719690309d769f1a3b5974f8bd7c693bd/examples)
<!--EXAMPLES-PREVIEW-->
- [Recent benchmark results](https://build.rerun.io/graphs/crates.html)
- [Wasm size tracking](https://build.rerun.io/graphs/sizes.html)

Cargo.toml

@@ -177,6 +177,7 @@ poll-promise = "0.3"
 pollster = "0.3"
 prettyplease = "0.2"
 proc-macro2 = { version = "1.0", default-features = false }
+profiling = { version = "1.0.12", default-features = false }
 puffin = "0.18"
 puffin_http = "0.15"
 pyo3 = "0.19.0"

crates/re_renderer/Cargo.toml

@@ -62,6 +62,9 @@ macaw.workspace = true
 never.workspace = true
 ordered-float.workspace = true
 parking_lot.workspace = true
+# wgpu uses the `profiling` crate for its profiling scopes.
+# This will hook them up to the puffin profiler as backend:
+profiling = { workspace = true, features = ["profile-with-puffin"] }
 slotmap.workspace = true
 smallvec.workspace = true
 static_assertions.workspace = true