chore: bump the minimum supported Rust version to 1.52.1 (#534)

- `const_fn` usage in the `bitflags` crate.
- `unsafe_op_in_unsafe_fn` lint usage in `rust_info` despite pinned `cargo-make` version.

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        rust: ["1.44.0", "stable"]
+        rust: ["1.52.1", "stable"]
     steps:
       - name: "Install dependencies"
         run: sudo apt-get install libncurses5-dev
@@ -53,7 +53,7 @@ jobs:
     runs-on: windows-latest
     strategy:
       matrix:
-        rust: ["1.44.0", "stable"]
+        rust: ["1.52.1", "stable"]
     steps:
       - uses: actions/checkout@v1
       - uses: hecrj/setup-rust-action@967aec96c6a27a0ce15c1dac3aaba332d60565e2