fix(cypress): move typings to a .d.ts file

Part-of: <https://dev.funkwhale.audio/funkwhale/funkwhale/-/merge_requests/1795>

front/cypress/cypress.d.ts

@@ -0,0 +1,7 @@
+declare global {
+  namespace Cypress {
+    interface Chainable {
+      login(): Chainable<JQuery<HTMLElement>>
+    }
+  }
+}

front/cypress/support/e2e.ts

@@ -1,9 +1 @@
 import './commands'
-
-declare global {
-  namespace Cypress {
-    interface Chainable {
-      login(): Chainable<JQuery<HTMLElement>>
-    }
-  }
-}

front/cypress/tsconfig.json

@@ -4,6 +4,6 @@
     "lib": ["es5", "dom"],
     "types": ["cypress", "node"]
   },
-  "include": ["**/*.ts"],
+  "include": ["**/*.ts", "./cypress.d.ts"],
   "isolatedModules": false
 }