Test cargo minimal versions on CI

With ron-rs/ron#557, we can test out lower bounds.

.github/workflows/ci.yml

@@ -16,8 +16,8 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@stable
-      - run: cargo build --verbose --workspace
-      - run: cargo test --all-features --workspace --verbose
+      - run: cargo build --workspace
+      - run: cargo test --all-features --workspace
 
   clippy:
     name: No warnings from Clippy
@@ -52,3 +52,13 @@ jobs:
         env:
           RUSTDOCFLAGS: -D warnings
         run: cargo doc --workspace --no-deps --document-private-items
+
+  minimal-versions:
+    name: Tests pass
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@nightly
+      - run: cargo +nightly update -Zminimal-versions
+      - run: cargo +nightly build --workspace
+      - run: cargo +nightly test --all-features --workspace

Cargo.toml

@@ -36,7 +36,7 @@ version-ranges = { version = "0.1.0", path = "version-ranges" }
 criterion = { version = "2.7.2", package = "codspeed-criterion-compat" }
 env_logger = "0.11.6"
 proptest = "1.6.0"
-ron = "=0.9.0-alpha.0"
+ron = { git = "https://github.com/ron-rs/ron/", branch = "minimup-deps" }
 varisat = "0.2.2"
 version-ranges = { version = "0.1.0", path = "version-ranges", features = ["proptest"] }