Update Rust crate waker-fn to v1.2.0 (#15289)

[![Mend
Renovate](https://app.renovatebot.com/images/banner.svg)](https://renovatebot.com)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [waker-fn](https://togithub.com/smol-rs/waker-fn) | dependencies |
minor | `1.1.0` -> `1.2.0` |

---

### Release Notes

<details>
<summary>smol-rs/waker-fn (waker-fn)</summary>

###
[`v1.2.0`](https://togithub.com/smol-rs/waker-fn/blob/HEAD/CHANGELOG.md#Version-120)

[Compare
Source](https://togithub.com/smol-rs/waker-fn/compare/v1.1.1...v1.2.0)

-   Add a new `portable-atomic` feature that allows for the usage of the
`portable-atomic` crate to implement `waker-fn`.
([#&#8203;10](https://togithub.com/smol-rs/waker-fn/issues/10))

###
[`v1.1.1`](https://togithub.com/smol-rs/waker-fn/blob/HEAD/CHANGELOG.md#Version-111)

[Compare
Source](https://togithub.com/smol-rs/waker-fn/compare/v1.1.0...v1.1.1)

- Reimplement using 100% safe code.
([#&#8203;7](https://togithub.com/smol-rs/waker-fn/issues/7))

</details>

---

### Configuration

📅 **Schedule**: Branch creation - "after 3pm on Wednesday" in timezone
America/New_York, Automerge - At any time (no schedule defined).

🚦 **Automerge**: Disabled by config. Please merge this manually once you
are satisfied.

♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the
rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update
again.

---

- [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check
this box

---

Release Notes:

- N/A

<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzNy40MzguMCIsInVwZGF0ZWRJblZlciI6IjM3LjQzOC4wIiwidGFyZ2V0QnJhbmNoIjoibWFpbiIsImxhYmVscyI6W119-->

---------

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>

crates/gpui/Cargo.toml

@@ -73,7 +73,7 @@ thiserror.workspace = true
 time.workspace = true
 util.workspace = true
 uuid.workspace = true
-waker-fn = "1.1.0"
+waker-fn = "1.2.0"
 
 [dev-dependencies]
 backtrace = "0.3"