Make module types explicit and convert some to ESM (#15964)

build-scripts/gulp/cast.cjs

@@ -0,0 +1,40 @@
+const gulp = require("gulp");
+const env = require("../env.cjs");
+
+require("./clean.cjs");
+require("./translations.cjs");
+require("./gather-static.cjs");
+require("./webpack.cjs");
+require("./service-worker.cjs");
+require("./entry-html.cjs");
+require("./rollup.cjs");
+
+gulp.task(
+  "develop-cast",
+  gulp.series(
+    async function setEnv() {
+      process.env.NODE_ENV = "development";
+    },
+    "clean-cast",
+    "translations-enable-merge-backend",
+    gulp.parallel("gen-icons-json", "build-translations", "build-locale-data"),
+    "copy-static-cast",
+    "gen-index-cast-dev",
+    env.useRollup() ? "rollup-dev-server-cast" : "webpack-dev-server-cast"
+  )
+);
+
+gulp.task(
+  "build-cast",
+  gulp.series(
+    async function setEnv() {
+      process.env.NODE_ENV = "production";
+    },
+    "clean-cast",
+    "translations-enable-merge-backend",
+    gulp.parallel("gen-icons-json", "build-translations", "build-locale-data"),
+    "copy-static-cast",
+    env.useRollup() ? "rollup-prod-cast" : "webpack-prod-cast",
+    "gen-index-cast-prod"
+  )
+);