Use prysmaticlabs/fastssz as a direct dependency (#10941)

* Update dependency

* Regenerate SSZ files

* fix BUILD files

Co-authored-by: Raul Jordan <raul@prysmaticlabs.com>
Co-authored-by: Preston Van Loon <preston@prysmaticlabs.com>
Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>

beacon-chain/slasher/BUILD.bazel

@@ -41,10 +41,10 @@ go_library(
         "//encoding/bytesutil:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//time/slots:go_default_library",
-        "@com_github_ferranbt_fastssz//:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prometheus_client_golang//prometheus:go_default_library",
         "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",
+        "@com_github_prysmaticlabs_fastssz//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
         "@io_opencensus_go//trace:go_default_library",
         "@org_golang_google_grpc//codes:go_default_library",
@@ -89,7 +89,7 @@ go_test(
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
         "//time/slots:go_default_library",
-        "@com_github_ferranbt_fastssz//:go_default_library",
+        "@com_github_prysmaticlabs_fastssz//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
         "@com_github_sirupsen_logrus//hooks/test:go_default_library",
     ],

beacon-chain/slasher/params.go

@@ -1,7 +1,7 @@
 package slasher
 
 import (
-	ssz "github.com/ferranbt/fastssz"
+	ssz "github.com/prysmaticlabs/fastssz"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
 )
 

beacon-chain/slasher/params_test.go

@@ -4,7 +4,7 @@ import (
 	"reflect"
 	"testing"
 
-	ssz "github.com/ferranbt/fastssz"
+	ssz "github.com/prysmaticlabs/fastssz"
 	types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/testing/assert"
 )