refactor(schematics): strongly type cypress pluginsFile params (#1127)

packages/schematics/src/collection/cypress-project/files/src/plugins/index.ts__tmpl__

@@ -11,7 +11,7 @@
 // This function is called when a project is opened or re-opened (e.g. due to
 // the project's config changing)
 
-module.exports = (on: any, config: any) => {
+module.exports = (on: Cypress.Actions, config: Cypress.ConfigOptions) => {
   // `on` is used to hook into various events Cypress emits
   // `config` is the resolved Cypress config
 };