cleanup: remove unneeded source format in read instruction

The image crate is able to infer the format, so that data is redundant

crates/eval/src/kind/debug/instr/mod.rs

@@ -2,7 +2,7 @@ pub mod read {
     use image::{io::Reader as ImageReader, DynamicImage};
     use ir::instruction::read::{Read, SourceType};
 
-    pub fn read(Read { source, .. }: Read) -> DynamicImage {
+    pub fn read(Read { source }: Read) -> DynamicImage {
         // TODO: actual error handling
         let img = ImageReader::open(match source {
             SourceType::File(path) => path,