make recent clippy happy

Cargo.toml

@@ -62,11 +62,6 @@ rust-2018-idioms = "deny"
 nonstandard-style = "deny"
 
 [lints.clippy]
-unwrap_used = "deny"
-unwrap_in_result = "deny"
-panic = "deny"
-expect_used = "deny"
-unimplemented = "deny"
 suspicious = "forbid"
 style = "forbid"
 complexity = "forbid"

lcov2cobertura/src/lib.rs

@@ -326,6 +326,8 @@ pub fn parse_lines<P: AsRef<Path>, B: BufRead>(
         let mut split = line.splitn(2, ':');
         let (input_type, line) = (split.next(), split.last());
 
+        // proposed improvement only works in rustc 1.63 and above
+        #[allow(clippy::assigning_clones)]
         match input_type {
             Some("SF") => {
                 let file_name = line.ok_or_else(|| anyhow::anyhow!("SF entry has no filename"))?;