buffer: Keep the shorter language setting names for the common operation (#43915)

cc
https://github.com/zed-industries/zed/pull/43888#issuecomment-3597265087

Release Notes:

- N/A *or* Added/Fixed/Improved ...

crates/edit_prediction_context/src/excerpt.rs

@@ -475,8 +475,7 @@ mod tests {
     use util::test::{generate_marked_text, marked_text_offsets_by};
 
     fn create_buffer(text: &str, cx: &mut TestAppContext) -> BufferSnapshot {
-        let buffer =
-            cx.new(|cx| Buffer::local(text, cx).with_language_immediate(rust_lang().into(), cx));
+        let buffer = cx.new(|cx| Buffer::local(text, cx).with_language(rust_lang().into(), cx));
         buffer.read_with(cx, |buffer, _| buffer.snapshot())
     }
 

crates/edit_prediction_context/src/imports.rs

@@ -1100,7 +1100,7 @@ mod test {
     ) {
         let buffer = cx.new(|cx| {
             let mut buffer = Buffer::local(source, cx);
-            buffer.set_language_immediate(Some(language.clone()), cx);
+            buffer.set_language(Some(language.clone()), cx);
             buffer
         });
         cx.run_until_parked();

crates/edit_prediction_context/src/reference.rs

@@ -148,9 +148,8 @@ mod test {
     }
 
     fn create_buffer(text: &str, cx: &mut TestAppContext) -> BufferSnapshot {
-        let buffer = cx.new(|cx| {
-            language::Buffer::local(text, cx).with_language_immediate(rust_lang().into(), cx)
-        });
+        let buffer =
+            cx.new(|cx| language::Buffer::local(text, cx).with_language(rust_lang().into(), cx));
         buffer.read_with(cx, |buffer, _| buffer.snapshot())
     }
 

crates/edit_prediction_context/src/syntax_index.rs

@@ -531,7 +531,7 @@ impl SyntaxIndex {
 
                 let buffer = cx.new(|cx| {
                     let mut buffer = Buffer::local(loaded_file.text, cx);
-                    buffer.set_language_immediate(Some(language.clone()), cx);
+                    buffer.set_language(Some(language.clone()), cx);
                     buffer
                 })?;