Update Rust minimum version to 1.86 (#117)

* Update Rust minimum version to 1.86

More details in this PR to bullet_stream heroku-buildpacks/bullet_stream#47. And this comment reporting the issue #110 (comment).

The short version is: This buildpack uses a dependency that accidentally uses a feature stabilized in Rust 1.86, but it didn't correctly update the minimum required Rust version. If it had, when #115 was merged, it would have also triggered the change that's now being made (I'm guessing this field is not linted, but I've not verified). This change corrects the problem by correctly stating the minimum Rust version so all dependencies can compile correctly.

* Update CHANGELOG.md

Co-authored-by: Ed Morley <[email protected]>
Signed-off-by: Richard Schneeman <[email protected]>

---------

Signed-off-by: Richard Schneeman <[email protected]>
Co-authored-by: Ed Morley <[email protected]>

Author: schneems

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Minimum supported Rust version incremented to 1.86 to support syntax introduced in [115](https://github.com/heroku/buildpacks-deb-packages/pull/115). ([#117](https://github.com/heroku/buildpacks-deb-packages/pull/117))
+
 ## [0.1.3] - 2025-04-01
 
 ### Added

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "buildpacks-deb-packages"
 edition = "2021"
-rust-version = "1.85"
+rust-version = "1.86"
 
 [build-dependencies]
 toml_edit = "0.22"