MM-54181 : Clean up code around deprecated Gfycat (#24343)

* first pass of removal

* first pass of removal

* Update admin_console.js

* rev beta

* remove more

* Update initial_state.ts

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

e2e-tests/cypress/tests/support/api/cloud_default_config.json

@@ -13,8 +13,6 @@
         "EnableCustomEmoji": false,
         "EnableEmojiPicker": true,
         "EnableGifPicker": false,
-        "GfycatAPIKey": "2_KtH_W5",
-        "GfycatAPISecret": "3wLVZPiswc3DnaiaFoLkDvB4X0IV6CpMkj4tf2inJRsBY6-FnkT08zGmppWFgeof",
         "PostEditTimeLimit": -1,
         "EnablePreviewFeatures": true,
         "EnableTutorial": true,

e2e-tests/cypress/tests/support/api/on_prem_default_config.json

@@ -52,8 +52,6 @@
         "EnableCustomEmoji": false,
         "EnableEmojiPicker": true,
         "EnableGifPicker": false,
-        "GfycatAPIKey": "2_KtH_W5",
-        "GfycatAPISecret": "3wLVZPiswc3DnaiaFoLkDvB4X0IV6CpMkj4tf2inJRsBY6-FnkT08zGmppWFgeof",
         "PostEditTimeLimit": -1,
         "TimeBetweenUserTypingUpdatesMilliseconds": 5000,
         "EnablePostSearch": true,