refactor: unify the error handling methods in the crypto package that are different from the project style

cl/beacon/builder/client.go

@@ -76,7 +76,7 @@ func (b *builderClient) RegisterValidator(ctx context.Context, registers []*clty
 		return err
 	}
 	_, err = httpCall[json.RawMessage](ctx, b.httpClient, http.MethodPost, url, nil, bytes.NewBuffer(payload))
-	if err == ErrNoContent {
+	if errors.Is(err, ErrNoContent) {
 		// no content is ok
 		return nil
 	}
@@ -144,7 +144,7 @@ func (b *builderClient) GetStatus(ctx context.Context) error {
 	path := "/eth/v1/builder/status"
 	url := b.url.JoinPath(path).String()
 	_, err := httpCall[json.RawMessage](ctx, b.httpClient, http.MethodGet, url, nil, nil)
-	if err == ErrNoContent {
+	if errors.Is(err, ErrNoContent) {
 		// no content is ok, we just need to check if the server is up
 		return nil
 	}

cl/beacon/handler/block_production.go

@@ -212,7 +212,7 @@ func (a *ApiHandler) GetEthV1ValidatorAttestationData(
 			*committeeIndex,
 		)
 
-		if err == attestation_producer.ErrHeadStateBehind {
+		if errors.Is(err, attestation_producer.ErrHeadStateBehind) {
 			return beaconhttp.NewEndpointError(
 				http.StatusServiceUnavailable,
 				synced_data.ErrNotSynced,

cl/phase1/forkchoice/on_block.go

@@ -188,7 +188,7 @@ func (f *ForkChoiceStore) OnBlock(ctx context.Context, block *cltypes.SignedBeac
 	// Check if blob data is available
 	if block.Version() >= clparams.DenebVersion && checkDataAvaiability {
 		if err := f.isDataAvailable(ctx, block.Block.Slot, blockRoot, block.Block.Body.BlobKzgCommitments); err != nil {
-			if err == ErrEIP4844DataNotAvailable {
+			if errors.Is(err, ErrEIP4844DataNotAvailable) {
 				return err
 			}
 			return fmt.Errorf("OnBlock: data is not available for block %x: %v", libcommon.Hash(blockRoot), err)

cl/phase1/network/services/block_service.go

@@ -159,7 +159,7 @@ func (b *blockService) ProcessMessage(ctx context.Context, _ *uint64, msg *cltyp
 	b.publishBlockGossipEvent(msg)
 	// the rest of the validation is done in the forkchoice store
 	if err := b.processAndStoreBlock(ctx, msg); err != nil {
-		if err == forkchoice.ErrEIP4844DataNotAvailable {
+		if errors.Is(err, forkchoice.ErrEIP4844DataNotAvailable) {
 			b.scheduleBlockForLaterProcessing(msg)
 			return ErrIgnore
 		}

rpc/subscription.go

@@ -260,7 +260,7 @@ func (sub *ClientSubscription) quitWithError(unsubscribeServer bool, err error)
 			sub.requestUnsubscribe()
 		}
 		if err != nil {
-			if err == ErrClientQuit {
+			if errors.Is(err, ErrClientQuit) {
 				err = nil // Adhere to subscription semantics.
 			}
 			sub.err <- err