ci: bump houseabsolute/actions-rust-cross from 0.0.14 to 0.0.15 (#401)

Bumps [houseabsolute/actions-rust-cross](https://github.com/houseabsolute/actions-rust-cross) from 0.0.14 to 0.0.15.
- [Release notes](https://github.com/houseabsolute/actions-rust-cross/releases)
- [Changelog](https://github.com/houseabsolute/actions-rust-cross/blob/v0/Changes.md)
- [Commits](houseabsolute/actions-rust-cross@ad283b2...e021eb0)

---
updated-dependencies:
- dependency-name: houseabsolute/actions-rust-cross
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

.github/workflows/test.yml

@@ -96,7 +96,7 @@ jobs:
         with:
           persist-credentials: false
 
-      - uses: houseabsolute/actions-rust-cross@ad283b2fc65ad1f3a04fb8bf8b2b829aad4a9318
+      - uses: houseabsolute/actions-rust-cross@e021eb0bd0406694c4c3bd14cfce45df810dfaa5
         with:
           command: build
           target: thumbv7em-none-eabi
@@ -116,7 +116,7 @@ jobs:
         with:
           persist-credentials: false
 
-      - uses: houseabsolute/actions-rust-cross@ad283b2fc65ad1f3a04fb8bf8b2b829aad4a9318
+      - uses: houseabsolute/actions-rust-cross@e021eb0bd0406694c4c3bd14cfce45df810dfaa5
         with:
           command: test
           target: ${{ matrix.arch }}