Update cargo-binstall to v1.15.6 (#21324)

# Objective

- Adopted from #21271.
- `cargo-binstall` in CI is outdated, let's update!

## Solution

- Update to v1.15.6 from v1.14.1.

## Testing

- As it's run in CI, the best way to test is to run CI! :)

## Notable Changes

-
[v1.14.2](https://github.com/cargo-bins/cargo-binstall/releases/tag/v1.14.2)
- Dependency updates
-
[v1.14.3](https://github.com/cargo-bins/cargo-binstall/releases/tag/v1.14.3)
- Fixes race condition
-
[v1.14.4](https://github.com/cargo-bins/cargo-binstall/releases/tag/v1.14.4)
- Switch from `fs4` to `std` for file locking
-
[v1.15.0](https://github.com/cargo-bins/cargo-binstall/releases/tag/v1.15.0)
- Prompt when using Quickinstall. ~~This may cause some issues in CI, I
need to investigate it further.~~
-
[v1.15.1](https://github.com/cargo-bins/cargo-binstall/releases/tag/v1.15.1)
- Fix issues with manifest file and Quickinstall prompt
-
[v1.15.2](https://github.com/cargo-bins/cargo-binstall/releases/tag/v1.15.2)
- Fix updating telemetry config file
-
[v1.15.3](https://github.com/cargo-bins/cargo-binstall/releases/tag/v1.15.3)
- Stop building for x86 MacOS
-
[v1.15.4](https://github.com/cargo-bins/cargo-binstall/releases/tag/v1.15.4)
- Docs and dependencies
-
[v1.15.5](https://github.com/cargo-bins/cargo-binstall/releases/tag/v1.15.5)
- Support Socks5 proxy
-
[v1.15.6](https://github.com/cargo-bins/cargo-binstall/releases/tag/v1.15.6)
- Update dependencies

---------

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: BD103

.github/workflows/ci.yml

@@ -19,7 +19,7 @@ env:
   # If nightly is breaking CI, modify this variable to target a specific nightly version.
   NIGHTLY_TOOLCHAIN: nightly
   RUSTFLAGS: "-D warnings"
-  BINSTALL_VERSION: "v1.14.1"
+  BINSTALL_VERSION: "v1.15.6"
 
 concurrency:
   group: ${{github.workflow}}-${{github.ref}}
@@ -318,7 +318,7 @@ jobs:
     steps:
       - uses: actions/checkout@v5
       # Update in sync with BINSTALL_VERSION
-      - uses: cargo-bins/[email protected].4
+      - uses: cargo-bins/[email protected].6
       - name: Install taplo
         run: cargo binstall [email protected] --locked
       - name: Run Taplo