Update embedded-io and impl for unsplit UART

.github/workflows/check.yml

@@ -98,7 +98,7 @@ jobs:
         uses: giraffate/clippy-action@v1
         with:
           reporter: 'github-pr-check'
-          clippy_flags: -- -F clippy::suspicious -F clippy::correctness -F clippy::perf -D clippy::style
+          clippy_flags: --locked -- -F clippy::suspicious -F clippy::correctness -F clippy::perf -D clippy::style
           github_token: ${{ secrets.GITHUB_TOKEN }}
 
   examples:
@@ -117,7 +117,7 @@ jobs:
       - name: Install stable
         uses: dtolnay/rust-toolchain@stable
       - name: cargo check
-        run: cargo check
+        run: cargo check --locked
         working-directory: ./examples
 
   # Enable once we have a released crate
@@ -160,7 +160,7 @@ jobs:
       - name: Install nightly
         uses: dtolnay/rust-toolchain@nightly
       - name: cargo doc
-        run: cargo doc --no-deps --all-features
+        run: cargo doc --locked --no-deps --all-features
         env:
           RUSTDOCFLAGS: --cfg docsrs
 
@@ -186,7 +186,7 @@ jobs:
       # intentionally no target specifier; see https://github.com/jonhoo/rust-ci-conf/pull/4
       # --feature-powerset runs for every combination of features
       - name: cargo hack
-        run: cargo hack --feature-powerset check
+        run: cargo hack --feature-powerset check --locked
 
   deny:
     # cargo-deny checks licenses, advisories, sources, and bans for
@@ -223,7 +223,7 @@ jobs:
       fail-fast: false
       matrix:
         commit: ${{ fromJSON(needs.commit_list.outputs.commits) }}
-        msrv: ["1.85"] # We're using edition 2024 in a dependency, introduced in 1.85
+        msrv: ["1.87"] # heapless 0.9.3 (via embassy-sync) requires 1.87
     name: ubuntu / ${{ matrix.msrv }} (${{ matrix.commit }})
     steps:
       - uses: actions/checkout@v4
@@ -235,4 +235,4 @@ jobs:
         with:
           toolchain: ${{ matrix.msrv }}
       - name: cargo +${{ matrix.msrv }} check
-        run: cargo check
+        run: cargo check --locked

.gitignore

@@ -3,10 +3,6 @@
 debug/
 target/
 
-# Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
-# More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
-Cargo.lock
-
 # These are backup files generated by rustfmt
 **/*.rs.bk