bump MSRV to the latest version

.github/workflows/checks.yml

@@ -31,7 +31,7 @@ jobs:
         with:
           # Fixed version for clippy lints.  Bump this as necesary.  It must not
           # be older than the MSRV in tests.yml.
-          toolchain: "1.57"
+          toolchain: "1.61"
           override: true
 
       - uses: actions-rs/cargo@v1.0.1

.github/workflows/rust-tests.yml

@@ -13,7 +13,7 @@ jobs:
       matrix:
         rust:
           # MSRV; must not be higher than the clippy rust version in checks.yml
-          - "1.54"
+          - "1.61"
           - "stable"
         os:
           - ubuntu-latest

rust/taskchampion/src/lib.rs

@@ -41,7 +41,7 @@ for more information about the design and usage of the tool.
 
 # Minimum Supported Rust Version (MSRV)
 
-This crate supports Rust version 1.54 and higher.
+This crate supports Rust version 1.61 and higher.
 
  */