chore: fix few nit build warnings (#2848)

Author: cijothomas

opentelemetry-otlp/src/exporter/tonic/mod.rs

@@ -514,6 +514,7 @@ mod tests {
         assert!(tonic::codec::CompressionEncoding::try_from(Compression::Zstd).is_err());
     }
 
+    #[cfg(feature = "zstd-tonic")]
     #[test]
     fn test_priority_of_signal_env_over_generic_env_for_compression() {
         run_env_test(
@@ -532,6 +533,7 @@ mod tests {
         );
     }
 
+    #[cfg(feature = "zstd-tonic")]
     #[test]
     fn test_priority_of_code_based_config_over_envs_for_compression() {
         run_env_test(

opentelemetry-otlp/tests/integration_test/src/logs_asserter.rs

@@ -1,8 +1,7 @@
 use anyhow::Result;
-use opentelemetry_proto::tonic::{
-    common::v1::KeyValue,
-    logs::v1::{LogRecord, LogsData, ResourceLogs},
-};
+#[cfg(feature = "experimental_metadata_attributes")]
+use opentelemetry_proto::tonic::common::v1::KeyValue;
+use opentelemetry_proto::tonic::logs::v1::{LogRecord, LogsData, ResourceLogs};
 use std::fs::File;
 
 // Given two ResourceLogs, assert that they are equal except for the timestamps