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/semantic_index/Cargo.toml

@@ -54,7 +54,6 @@ workspace-hack.workspace = true
 
 [dev-dependencies]
 client = { workspace = true, features = ["test-support"] }
-env_logger.workspace = true
 fs = { workspace = true, features = ["test-support"] }
 futures.workspace = true
 gpui = { workspace = true, features = ["test-support"] }
@@ -67,3 +66,4 @@ reqwest_client.workspace = true
 util = { workspace = true, features = ["test-support"] }
 workspace = { workspace = true, features = ["test-support"] }
 worktree = { workspace = true, features = ["test-support"] }
+zlog.workspace = true

crates/semantic_index/examples/index.rs

@@ -12,7 +12,7 @@ use std::{
 };
 
 fn main() {
-    env_logger::init();
+    zlog::init();
 
     use clock::FakeSystemClock;
 

crates/semantic_index/src/semantic_index.rs

@@ -280,7 +280,7 @@ mod tests {
     use util::separator;
 
     fn init_test(cx: &mut TestAppContext) {
-        env_logger::try_init().ok();
+        zlog::init_test();
 
         cx.update(|cx| {
             let store = SettingsStore::test(cx);