package-lock.json: run npm audit fix

Even though I thought I had just done this, when I ran all.bash,
npm audit complained. This CL is the result of running

    ./all.bash npm audit fix

Change-Id: I00f4d8059bb9f44ba97a3e0118d40216eea08060
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/413034
Run-TryBot: Jonathan Amsterdam <jba@google.com>
Reviewed-by: Jamal Carvalho <jamal@golang.org>
TryBot-Result: kokoro <noreply+kokoro@google.com>
diff --git a/package-lock.json b/package-lock.json
index 55efc67..e4538f3 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -4756,9 +4756,9 @@
       }
     },
     "minimist": {
-      "version": "1.2.5",
-      "resolved": "https://registry.npmjs.org/minimist/-/minimist-1.2.5.tgz",
-      "integrity": "sha512-FM9nNUYrRBAELZQT3xeZQ7fmMOBg6nWNmJKTcgsJeaLstP/UODVpGsr5OhXhhXg6f+qtJ8uiZ+PUxkDWcgIXLw=="
+      "version": "1.2.6",
+      "resolved": "https://registry.npmjs.org/minimist/-/minimist-1.2.6.tgz",
+      "integrity": "sha512-Jsjnk4bw3YJqYzbdyBiNsPWHPfO++UGG749Cxs6peCu5Xg4nrena6OVxOYxrQTqww0Jmwt+Ref8rggumkTLz9Q=="
     },
     "minimist-options": {
       "version": "4.1.0",