refactor: remove unused macro

Closes pjd#45.

rust/src/runner/mod.rs

@@ -1,24 +1 @@
 pub mod context;
-
-/// Macro which expands to a function which executes the tests.
-#[macro_export]
-macro_rules! pjdfs_main {
-    ($( $test:path ),+) => {
-        fn main() -> anyhow::Result<()> {
-            for group in &[ $( $test ),+ ] {
-                for test_case in group.test_cases.iter() {
-                    for test in test_case.tests {
-                        println!(
-                            "{}\t",
-                            format!("{}::{}::{}", group.name, test_case.name, test.name)
-                        );
-                        let mut context = TestContext::new();
-                        (test.fun)(&mut context)?;
-                    }
-                }
-            }
-
-            Ok(())
-        }
-    };
-}