refactor: remove unused QueryExec impl

This is completely unused and left over from the initial skeleton.

ingester2/src/query/exec.rs

@@ -1,40 +0,0 @@
-use async_trait::async_trait;
-use data_types::{NamespaceId, TableId};
-use observability_deps::tracing::*;
-use trace::span::{Span, SpanRecorder};
-
-use super::{QueryError, QueryExec};
-use crate::query::response::QueryResponse;
-
-#[derive(Debug)]
-pub(crate) struct QueryRunner;
-
-impl QueryRunner {
-    pub(crate) fn new() -> Self {
-        Self {}
-    }
-}
-
-#[async_trait]
-impl QueryExec for QueryRunner {
-    type Response = QueryResponse;
-
-    async fn query_exec(
-        &self,
-        namespace_id: NamespaceId,
-        table_id: TableId,
-        columns: Vec<String>,
-        span: Option<Span>,
-    ) -> Result<Self::Response, QueryError> {
-        let mut _span_recorder = SpanRecorder::new(span);
-
-        info!(
-            namespace_id=%namespace_id,
-            table_id=%table_id,
-            columns=?columns,
-            "executing query"
-        );
-
-        unimplemented!();
-    }
-}

ingester2/src/query/mod.rs

@@ -7,7 +7,7 @@ pub(crate) use r#trait::*;
 pub(crate) mod partition_response;
 pub(crate) mod response;
 
-pub(crate) mod exec;
+// Instrumentation
 pub(crate) mod instrumentation;
 pub(crate) mod tracing;