Declare and verify MSRV

Author: Gianmarco Garrisi

.github/workflows/static-checks.yml

@@ -34,3 +34,11 @@ jobs:
         with:
           components: miri
       - run: cargo miri test
+
+  msrv-verify:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@master
+      - run: cargo install cargo-msrv
+      - run: cargo msrv verify

Cargo.toml

@@ -10,6 +10,7 @@ keywords = ["priority", "queue", "heap"]
 categories = ["data-structures", "algorithms"]
 license = "LGPL-3.0-or-later OR MPL-2.0"
 edition = "2021"
+rust-version = "1.65.0"
 
 [build-dependencies]
 autocfg = "1"