Add CI job using minimal-versions

.github/workflows/ci.yml

@@ -128,6 +128,16 @@ jobs:
       - uses: dtolnay/rust-toolchain@1.36.0
       - run: cd serde && cargo build --no-default-features --features alloc
 
+  minimal:
+    name: Minimal versions
+    runs-on: ubuntu-latest
+    timeout-minutes: 45
+    steps:
+      - uses: actions/checkout@v3
+      - uses: dtolnay/rust-toolchain@nightly
+      - run: cargo generate-lockfile -Z minimal-versions
+      - run: cargo check --locked --workspace
+
   clippy:
     name: Clippy
     runs-on: ubuntu-latest