zlog: Replace usages of env_logger in tests with zlog (#31436)

Also fixes:
https://github.com/zed-industries/zed/pull/31400#issuecomment-2908165249

Release Notes:

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

crates/dap/Cargo.toml

@@ -53,8 +53,8 @@ workspace-hack.workspace = true
 
 [dev-dependencies]
 async-pipe.workspace = true
-env_logger.workspace = true
 gpui = { workspace = true, features = ["test-support"] }
 settings = { workspace = true, features = ["test-support"] }
 task = { workspace = true, features = ["test-support"] }
 util = { workspace = true, features = ["test-support"] }
+zlog.workspace = true

crates/dap/src/client.rs

@@ -281,9 +281,7 @@ mod tests {
     };
 
     pub fn init_test(cx: &mut gpui::TestAppContext) {
-        if std::env::var("RUST_LOG").is_ok() {
-            env_logger::try_init().ok();
-        }
+        zlog::init_test();
 
         cx.update(|cx| {
             let settings = SettingsStore::test(cx);