[Security] Bump sshpk from 1.13.1 to 1.15.2

Bumps [sshpk](https://github.com/joyent/node-sshpk) from 1.13.1 to 1.15.2. **This update includes security fixes.**
- [Release notes](https://github.com/joyent/node-sshpk/releases)
- [Commits](TritonDataCenter/node-sshpk@v1.13.1...v1.15.2)

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

yarn.lock

@@ -6206,6 +6206,11 @@ safe-regex@^1.1.0:
   dependencies:
     ret "~0.1.10"
 
+safer-buffer@^2.0.2:
+  version "2.1.2"
+  resolved "https://registry.yarnpkg.com/safer-buffer/-/safer-buffer-2.1.2.tgz#44fa161b0187b9549dd84bb91802f9bd8385cd6a"
+  integrity sha512-YZo3K82SD7Riyi0E1EQPojLz7kpepnSQI9IyPbHHg1XXXevb5dJI7tpyN2ADxGcQbHG7vcyRHk0cbwqcQriUtg==
+
 sass-graph@^2.2.4:
   version "2.2.4"
   resolved "https://registry.yarnpkg.com/sass-graph/-/sass-graph-2.2.4.tgz#13fbd63cd1caf0908b9fd93476ad43a51d1e0b49"
@@ -6615,18 +6620,18 @@ sprintf-js@~1.0.2:
   integrity sha1-BOaSb2YolTVPPdAVIDYzuFcpfiw=
 
 sshpk@^1.7.0:
-  version "1.13.1"
-  resolved "https://registry.yarnpkg.com/sshpk/-/sshpk-1.13.1.tgz#512df6da6287144316dc4c18fe1cf1d940739be3"
-  integrity sha1-US322mKHFEMW3EwY/hzx2UBzm+M=
+  version "1.15.2"
+  resolved "https://registry.yarnpkg.com/sshpk/-/sshpk-1.15.2.tgz#c946d6bd9b1a39d0e8635763f5242d6ed6dcb629"
+  integrity sha512-Ra/OXQtuh0/enyl4ETZAfTaeksa6BXks5ZcjpSUNrjBr0DvrJKX+1fsKDPpT9TBXgHAFsa4510aNVgI8g/+SzA==
   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"
 
 ssri@^5.0.0, ssri@^5.2.4: