[k187] Spans: Stop emitting GetChunks and IndexClient.GetChunkRefs (

#11830)

Backport 3b7ac35 from #11825

---

**What this PR does / why we need it**:
Modify our code to not emit the `GetChunks` and the
`IndexClient.GetChunkRefs` spans.
We don't worse our observability by getting rid of them because their
data is redundant with parent spans. Example:
- If an specific index-gateway or ingester struggles, the parent span
`/logproto.Querier/GetChunkIDs` will report it just fine
- If an specific query causes trouble the `query.Exec` span will show
the query name, the `start` and `end`, etc. Also, its children will show
the slower parts of the query (in case we have a weak link)

**Which issue(s) this PR fixes**:
N/A

Co-authored-by: Dylan Guedes <[email protected]>

pkg/storage/stores/composite_store_entry.go

@@ -46,18 +46,8 @@ func (c *storeEntry) GetChunks(ctx context.Context, userID string, from, through
 	if ctx.Err() != nil {
 		return nil, nil, ctx.Err()
 	}
-	sp, ctx := opentracing.StartSpanFromContext(ctx, "GetChunks")
-	defer sp.Finish()
-	log := spanlogger.FromContext(ctx)
-	defer log.Span.Finish()
 
 	shortcut, err := c.validateQueryTimeRange(ctx, userID, &from, &through)
-	level.Debug(log).Log(
-		"shortcut", shortcut,
-		"from", from.Time(),
-		"through", through.Time(),
-		"err", err,
-	)
 	if err != nil {
 		return nil, nil, err
 	} else if shortcut {

pkg/storage/stores/shipper/indexshipper/tsdb/index_client.go

@@ -105,32 +105,13 @@ func cleanMatchers(matchers ...*labels.Matcher) ([]*labels.Matcher, *index.Shard
 // They share almost the same fields, so we can add the missing `KB` field to the proto and then
 // use that within the tsdb package.
 func (c *IndexClient) GetChunkRefs(ctx context.Context, userID string, from, through model.Time, predicate chunk.Predicate) ([]logproto.ChunkRef, error) {
-	sp, ctx := opentracing.StartSpanFromContext(ctx, "IndexClient.GetChunkRefs")
-	defer sp.Finish()
-
-	var kvps []interface{}
-	defer func() {
-		sp.LogKV(kvps...)
-	}()
-
 	matchers, shard, err := cleanMatchers(predicate.Matchers...)
-	kvps = append(kvps,
-		"from", from.Time(),
-		"through", through.Time(),
-		"matchers", syntax.MatchersString(matchers),
-		"shard", shard,
-		"cleanMatcherErr", err,
-	)
 	if err != nil {
 		return nil, err
 	}
 
 	// TODO(owen-d): use a pool to reduce allocs here
 	chks, err := c.idx.GetChunkRefs(ctx, userID, from, through, nil, shard, matchers...)
-	kvps = append(kvps,
-		"chunks", len(chks),
-		"indexErr", err,
-	)
 	if err != nil {
 		return nil, err
 	}