Remove redundant call to DiagnosticsReporter::ensure (#1604)

Ensure will be called by `compile_test_prepared_db`
https://github.com/starkware-libs/cairo/blob/8f96af509b3270809fe7ec6fa9be5c6907b4b97d/crates/cairo-lang-test-plugin/src/lib.rs#L75C8-L75C9
which in turn calls `ensure` here
https://github.com/starkware-libs/cairo/blob/8f96af509b3270809fe7ec6fa9be5c6907b4b97d/crates/cairo-lang-compiler/src/lib.rs#L224

scarb/src/compiler/compilers/test.rs

@@ -32,11 +32,9 @@ impl Compiler for TestCompiler {
                 && plugin.package.id.source_id == SourceId::for_std()
         });
 
-        let mut diagnostics_reporter =
+        let diagnostics_reporter =
             build_compiler_config(db, &unit, &test_crate_ids, ws).diagnostics_reporter;
 
-        diagnostics_reporter.ensure(db)?;
-
         let test_compilation = {
             let _ = trace_span!("compile_test").enter();
             let config = TestsCompilationConfig {