[Security] Bump sshpk from 1.13.1 to 1.15.1

Bumps [sshpk](https://github.com/joyent/node-sshpk) from 1.13.1 to 1.15.1. **This update includes security fixes.**
- [Release notes](https://github.com/joyent/node-sshpk/releases)
- [Commits](TritonDataCenter/node-sshpk@v1.13.1...v1.15.1)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Author: dependabot-support

yarn.lock

@@ -6793,6 +6793,10 @@ safe-json-parse@~1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/safe-json-parse/-/safe-json-parse-1.0.1.tgz#3e76723e38dfdda13c9b1d29a1e07ffee4b30b57"
 
+safer-buffer@^2.0.2:
+  version "2.1.2"
+  resolved "https://registry.yarnpkg.com/safer-buffer/-/safer-buffer-2.1.2.tgz#44fa161b0187b9549dd84bb91802f9bd8385cd6a"
+
 sane@^1.1.1:
   version "1.7.0"
   resolved "https://registry.yarnpkg.com/sane/-/sane-1.7.0.tgz#b3579bccb45c94cf20355cc81124990dfd346e30"
@@ -7146,17 +7150,17 @@ sri-toolbox@^0.2.0:
   resolved "https://registry.yarnpkg.com/sri-toolbox/-/sri-toolbox-0.2.0.tgz#a7fea5c3fde55e675cf1c8c06f3ebb5c2935835e"
 
 sshpk@^1.7.0:
-  version "1.13.1"
-  resolved "https://registry.yarnpkg.com/sshpk/-/sshpk-1.13.1.tgz#512df6da6287144316dc4c18fe1cf1d940739be3"
+  version "1.15.1"
+  resolved "https://registry.yarnpkg.com/sshpk/-/sshpk-1.15.1.tgz#b79a089a732e346c6e0714830f36285cd38191a2"
   dependencies:
     asn1 "~0.2.3"
     assert-plus "^1.0.0"
-    dashdash "^1.12.0"
-    getpass "^0.1.1"
-  optionalDependencies:
     bcrypt-pbkdf "^1.0.0"
+    dashdash "^1.12.0"
     ecc-jsbn "~0.1.1"
+    getpass "^0.1.1"
     jsbn "~0.1.0"
+    safer-buffer "^2.0.2"
     tweetnacl "~0.14.0"
 
 static-extend@^0.1.1: