Vendored github.com/tyler-smith/go-bip39 (#16015)

* Vendor go-bip39 dependency locally to third_party/

The github.com/tyler-smith/go-bip39 repository has been deleted from GitHub 
but is still needed for BIP-39 mnemonic functionality in the validator wallet 
system. This change vendors v1.1.0 of the library into third_party/go-bip39/ 
to ensure continued availability.

Changes:
- Copy go-bip39 v1.1.0 source from Go module cache to third_party/go-bip39/
- Create BUILD.bazel files for main package and wordlists subpackage
- Update 5 BUILD.bazel files to reference local vendored version instead of external dependency
- Remove go-bip39 from go.mod and deps.bzl
- All builds and tests pass successfully

The vendored package includes all 9 language wordlists (English, Chinese Simplified/Traditional, 
Czech, French, Italian, Japanese, Korean, Spanish) and maintains the original import paths for 
compatibility.

* Changelog fraagment

* use go mod replace for vendored lib

* Run gazelle

---------

Co-authored-by: Kasey Kirkham <kasey@users.noreply.github.com>

cmd/validator/wallet/BUILD.bazel

@@ -15,6 +15,8 @@ go_library(
         "//config/features:go_default_library",
         "//io/prompt:go_default_library",
         "//runtime/tos:go_default_library",
+        "//third_party/go-bip39:go_default_library",
+        "//third_party/go-bip39/wordlists:go_default_library",
         "//validator/accounts:go_default_library",
         "//validator/accounts/userprompt:go_default_library",
         "//validator/accounts/wallet:go_default_library",
@@ -22,8 +24,6 @@ go_library(
         "@com_github_manifoldco_promptui//:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
-        "@com_github_tyler_smith_go_bip39//:go_default_library",
-        "@com_github_tyler_smith_go_bip39//wordlists:go_default_library",
         "@com_github_urfave_cli_v2//:go_default_library",
     ],
 )