cleanup: remove unneeded source format in read instruction

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

crates/ir/src/instruction/read.rs

@@ -4,16 +4,9 @@ use std::path::PathBuf;
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
 pub struct Read {
     pub source: SourceType,
-    pub format: SourceFormat,
 }
 
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
 pub enum SourceType {
     File(PathBuf),
 }
-
-#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
-pub enum SourceFormat {
-    Jpeg,
-    Png,
-}