fix(share/shrex): return aggregated error if context Deadline reached (…

…#2243)

## Overview

Errors were lost on context deadline

share/getters/shrex.go

@@ -130,19 +130,18 @@ func (sg *ShrexGetter) GetEDS(ctx context.Context, root *share.Root) (*rsmt2d.Ex
 	for {
 		if ctx.Err() != nil {
 			sg.metrics.recordEDSAttempt(ctx, attempt, false)
-			return nil, ctx.Err()
+			return nil, errors.Join(err, ctx.Err())
 		}
 		attempt++
 		start := time.Now()
 		peer, setStatus, getErr := sg.peerManager.Peer(ctx, root.Hash())
 		if getErr != nil {
-			err = errors.Join(err, getErr)
 			log.Debugw("eds: couldn't find peer",
 				"hash", root.String(),
 				"err", getErr,
 				"finished (s)", time.Since(start))
 			sg.metrics.recordEDSAttempt(ctx, attempt, false)
-			return nil, fmt.Errorf("getter/shrex: %w", err)
+			return nil, errors.Join(err, getErr)
 		}
 
 		reqStart := time.Now()
@@ -197,19 +196,18 @@ func (sg *ShrexGetter) GetSharesByNamespace(
 	for {
 		if ctx.Err() != nil {
 			sg.metrics.recordNDAttempt(ctx, attempt, false)
-			return nil, ctx.Err()
+			return nil, errors.Join(err, ctx.Err())
 		}
 		attempt++
 		start := time.Now()
 		peer, setStatus, getErr := sg.peerManager.Peer(ctx, root.Hash())
 		if getErr != nil {
-			err = errors.Join(err, getErr)
 			log.Debugw("nd: couldn't find peer",
 				"hash", root.String(),
 				"err", getErr,
 				"finished (s)", time.Since(start))
 			sg.metrics.recordNDAttempt(ctx, attempt, false)
-			return nil, fmt.Errorf("getter/shrex: %w", err)
+			return nil, errors.Join(err, getErr)
 		}
 
 		reqStart := time.Now()