clippy and msrv fix

.github/workflows/ci.yml

@@ -27,7 +27,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: 1.61.0
+          toolchain: 1.65.0
           override: true
           profile: minimal
       - uses: actions-rs/cargo@v1

src/ecss/mod.rs

@@ -245,7 +245,7 @@ pub(crate) fn verify_crc16_ccitt_false_from_raw_to_pus_error(
     crc16: u16,
 ) -> Result<(), PusError> {
     verify_crc16_ccitt_false_from_raw(raw_data)
-        .then(|| ())
+        .then_some(())
         .ok_or(PusError::ChecksumFailure(crc16))
 }