Bump sshpk from 1.13.1 to 1.16.1

Bumps [sshpk](https://github.com/joyent/node-sshpk) from 1.13.1 to 1.16.1.
- [Release notes](https://github.com/joyent/node-sshpk/releases)
- [Commits](https://github.com/joyent/node-sshpk/compare/v1.13.1...v1.16.1)

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

package-lock.json

@@ -973,14 +973,14 @@
             "dev": true,
             "optional": true,
             "requires": {
-                "asn1": "0.2.3",
-                "assert-plus": "1.0.0",
-                "bcrypt-pbkdf": "1.0.1",
-                "dashdash": "1.14.1",
-                "ecc-jsbn": "0.1.1",
-                "getpass": "0.1.7",
-                "jsbn": "0.1.1",
-                "tweetnacl": "0.14.5"
+                "asn1": "~0.2.3",
+                "assert-plus": "^1.0.0",
+                "bcrypt-pbkdf": "^1.0.0",
+                "dashdash": "^1.12.0",
+                "ecc-jsbn": "~0.1.1",
+                "getpass": "^0.1.1",
+                "jsbn": "~0.1.0",
+                "tweetnacl": "~0.14.0"
             },
             "dependencies": {
                 "assert-plus": {