Bump ajv from 6.10.2 to 6.12.6 in /functions

Bumps [ajv](https://github.com/ajv-validator/ajv) from 6.10.2 to 6.12.6.
- [Release notes](https://github.com/ajv-validator/ajv/releases)
- [Commits](https://github.com/ajv-validator/ajv/compare/v6.10.2...v6.12.6)

---
updated-dependencies:
- dependency-name: ajv
  dependency-type: indirect
...

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

functions/package-lock.json

@@ -518,15 +518,23 @@
       }
     },
     "ajv": {
-      "version": "6.10.2",
-      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.10.2.tgz",
-      "integrity": "sha512-TXtUUEYHuaTEbLZWIKUr5pmBuhDLy+8KYtPYdcV8qC+pOZL+NKqYwvWSRrVXHn+ZmRRAu8vJTAznH7Oag6RVRw==",
+      "version": "6.12.6",
+      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.12.6.tgz",
+      "integrity": "sha512-j3fVLgvTo527anyYyJOGTYJbG+vnnQYvE0m5mmkc1TK+nxAppkCLMIL0aZ4dblVCNoGShhm+kzE4ZUykBoMg4g==",
       "dev": true,
       "requires": {
-        "fast-deep-equal": "^2.0.1",
+        "fast-deep-equal": "^3.1.1",
         "fast-json-stable-stringify": "^2.0.0",
         "json-schema-traverse": "^0.4.1",
         "uri-js": "^4.2.2"
+      },
+      "dependencies": {
+        "fast-deep-equal": {
+          "version": "3.1.3",
+          "resolved": "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-3.1.3.tgz",
+          "integrity": "sha512-f3qQ9oQy9j2AhBe/H9VC91wLmKBCCU/gDOnKNAYG5hswO7BLKj09Hc5HYNz9cGI++xlpDCIgDaitVs03ATR84Q==",
+          "dev": true
+        }
       }
     },
     "ansi-escapes": {
@@ -1404,12 +1412,6 @@
         "tmp": "^0.0.33"
       }
     },
-    "fast-deep-equal": {
-      "version": "2.0.1",
-      "resolved": "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-2.0.1.tgz",
-      "integrity": "sha1-ewUhjd+WZ79/Nwv3/bLLFf3Qqkk=",
-      "dev": true
-    },
     "fast-json-stable-stringify": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/fast-json-stable-stringify/-/fast-json-stable-stringify-2.0.0.tgz",
@@ -3715,9 +3717,9 @@
       "integrity": "sha512-LKYU1iAXJXUgAXn9URjiu+MWhyUXHsvfp7mcuYm9dSUKK0/CjtrUwFAxD82/mCWbtLsGjFIad0wIsod4zrTAEQ=="
     },
     "y18n": {
-      "version": "3.2.2",
-      "resolved": "https://registry.npmjs.org/y18n/-/y18n-3.2.2.tgz",
-      "integrity": "sha512-uGZHXkHnhF0XeeAPgnKfPv1bgKAYyVvmNL1xlKsPYZPaIHxGti2hHqvOCQv71XMsLxu1QjergkqogUnms5D3YQ=="
+      "version": "3.2.1",
+      "resolved": "https://registry.npmjs.org/y18n/-/y18n-3.2.1.tgz",
+      "integrity": "sha1-bRX7qITAhnnA136I53WegR4H+kE="
     },
     "yallist": {
       "version": "3.0.3",