Update dependency react-helmet to v6

gatsby-theme-addthis/package.json

@@ -17,6 +17,6 @@
     "gatsby": "^2.18.25 || ^3.0.0"
   },
   "dependencies": {
-    "react-helmet": "^5.2.1"
+    "react-helmet": "^6.0.0"
   }
 }

yarn.lock

@@ -4702,11 +4702,6 @@ execa@^4.0.2, execa@^4.0.3:
     signal-exit "^3.0.2"
     strip-final-newline "^2.0.0"
 
-exenv@^1.2.1:
-  version "1.2.2"
-  resolved "https://registry.yarnpkg.com/exenv/-/exenv-1.2.2.tgz#2ae78e85d9894158670b03d47bec1f03bd91bb9d"
-  integrity sha1-KueOhdmJQVhnCwPUe+wfA72Ru50=
-
 expand-brackets@^2.1.4:
   version "2.1.4"
   resolved "https://registry.yarnpkg.com/expand-brackets/-/expand-brackets-2.1.4.tgz#b77735e315ce30f6b6eff0f83b04151a22449622"
@@ -9291,7 +9286,7 @@ prompts@^2.3.2:
     kleur "^3.0.3"
     sisteransi "^1.0.5"
 
-prop-types@^15.5.4, prop-types@^15.6.1, prop-types@^15.6.2, prop-types@^15.7.2:
+prop-types@^15.6.1, prop-types@^15.6.2, prop-types@^15.7.2:
   version "15.7.2"
   resolved "https://registry.yarnpkg.com/prop-types/-/prop-types-15.7.2.tgz#52c41e75b8c87e72b9d9360e0206b99dcbffa6c5"
   integrity sha512-8QQikdH7//R2vurIJSutZ1smHYTcLpRWEOlHnzcWHmBYrOGUysKwSsrC89BCiFj3CbrfJ/nXFdJepOVrY1GCHQ==
@@ -9503,20 +9498,20 @@ react-error-overlay@^6.0.9:
   resolved "https://registry.yarnpkg.com/react-error-overlay/-/react-error-overlay-6.0.9.tgz#3c743010c9359608c375ecd6bc76f35d93995b0a"
   integrity sha512-nQTTcUu+ATDbrSD1BZHr5kgSD4oF8OFjxun8uAaL8RwPBacGBNPf/yAuVVdx17N8XNzRDMrZ9XcKZHCjPW+9ew==
 
-react-fast-compare@^2.0.2:
-  version "2.0.4"
-  resolved "https://registry.yarnpkg.com/react-fast-compare/-/react-fast-compare-2.0.4.tgz#e84b4d455b0fec113e0402c329352715196f81f9"
-  integrity sha512-suNP+J1VU1MWFKcyt7RtjiSWUjvidmQSlqu+eHslq+342xCbGTYmC0mEhPCOHxlW0CywylOC1u2DFAT+bv4dBw==
+react-fast-compare@^3.1.1:
+  version "3.2.0"
+  resolved "https://registry.yarnpkg.com/react-fast-compare/-/react-fast-compare-3.2.0.tgz#641a9da81b6a6320f270e89724fb45a0b39e43bb"
+  integrity sha512-rtGImPZ0YyLrscKI9xTpV8psd6I8VAtjKCzQDlzyDvqJA8XOW78TXYQwNRNd8g8JZnDu8q9Fu/1v4HPAVwVdHA==
 
-react-helmet@^5.2.1:
-  version "5.2.1"
-  resolved "https://registry.yarnpkg.com/react-helmet/-/react-helmet-5.2.1.tgz#16a7192fdd09951f8e0fe22ffccbf9bb3e591ffa"
-  integrity sha512-CnwD822LU8NDBnjCpZ4ySh8L6HYyngViTZLfBBb3NjtrpN8m49clH8hidHouq20I51Y6TpCTISCBbqiY5GamwA==
+react-helmet@^6.0.0:
+  version "6.1.0"
+  resolved "https://registry.yarnpkg.com/react-helmet/-/react-helmet-6.1.0.tgz#a750d5165cb13cf213e44747502652e794468726"
+  integrity sha512-4uMzEY9nlDlgxr61NL3XbKRy1hEkXmKNXhjbAIOVw5vcFrsdYbH2FEwcNyWvWinl103nXgzYNlns9ca+8kFiWw==
   dependencies:
     object-assign "^4.1.1"
-    prop-types "^15.5.4"
-    react-fast-compare "^2.0.2"
-    react-side-effect "^1.1.0"
+    prop-types "^15.7.2"
+    react-fast-compare "^3.1.1"
+    react-side-effect "^2.1.0"
 
 react-is@^16.12.0:
   version "16.13.1"
@@ -9538,13 +9533,10 @@ react-refresh@^0.9.0:
   resolved "https://registry.yarnpkg.com/react-refresh/-/react-refresh-0.9.0.tgz#71863337adc3e5c2f8a6bfddd12ae3bfe32aafbf"
   integrity sha512-Gvzk7OZpiqKSkxsQvO/mbTN1poglhmAV7gR/DdIrRrSMXraRQQlfikRJOr3Nb9GTMPC5kof948Zy6jJZIFtDvQ==
 
-react-side-effect@^1.1.0:
-  version "1.1.5"
-  resolved "https://registry.yarnpkg.com/react-side-effect/-/react-side-effect-1.1.5.tgz#f26059e50ed9c626d91d661b9f3c8bb38cd0ff2d"
-  integrity sha512-Z2ZJE4p/jIfvUpiUMRydEVpQRf2f8GMHczT6qLcARmX7QRb28JDBTpnM2g/i5y/p7ZDEXYGHWg0RbhikE+hJRw==
-  dependencies:
-    exenv "^1.2.1"
-    shallowequal "^1.0.1"
+react-side-effect@^2.1.0:
+  version "2.1.1"
+  resolved "https://registry.yarnpkg.com/react-side-effect/-/react-side-effect-2.1.1.tgz#66c5701c3e7560ab4822a4ee2742dee215d72eb3"
+  integrity sha512-2FoTQzRNTncBVtnzxFOk2mCpcfxQpenBMbk5kSVBg5UcPqV9fRbgY2zhb7GTWWOlpFmAxhClBDlIq8Rsubz1yQ==
 
 react@^16.8.6:
   version "16.8.6"
@@ -10254,11 +10246,6 @@ shallow-compare@^1.2.2:
   resolved "https://registry.yarnpkg.com/shallow-compare/-/shallow-compare-1.2.2.tgz#fa4794627bf455a47c4f56881d8a6132d581ffdb"
   integrity sha512-LUMFi+RppPlrHzbqmFnINTrazo0lPNwhcgzuAXVVcfy/mqPDrQmHAyz5bvV0gDAuRFrk804V0HpQ6u9sZ0tBeg==
 
-shallowequal@^1.0.1:
-  version "1.1.0"
-  resolved "https://registry.yarnpkg.com/shallowequal/-/shallowequal-1.1.0.tgz#188d521de95b9087404fd4dcb68b13df0ae4e7f8"
-  integrity sha512-y0m1JoUZSlPAjXVtPPW70aZWfIL/dSP7AFkRnniLCrK/8MDKog3TySTBmckD+RObVxH0v4Tox67+F14PdED2oQ==
-
 shebang-command@^1.2.0:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/shebang-command/-/shebang-command-1.2.0.tgz#44aac65b695b03398968c39f363fee5deafdf1ea"