remove empty es6 group; reference original ts_library instead

ts/congrats/BUILD.bazel

@@ -32,9 +32,6 @@ ts_library(
 
 rollup_bundle(
     name = "congrats",
-    srcs = [
-        "//ts/lib:es6",
-    ],
     config_file = "//ts:rollup.config.js",
     entry_point = "bootstrap.ts",
     format = "iife",
@@ -45,6 +42,7 @@ rollup_bundle(
     deps = [
         "CongratsPage",
         "bootstrap",
+        "//ts/lib",
         "@npm//@rollup/plugin-commonjs",
         "@npm//@rollup/plugin-node-resolve",
         "@npm//rollup-plugin-terser",

ts/graphs/BUILD.bazel

@@ -76,9 +76,6 @@ ts_library(
 
 rollup_bundle(
     name = "graphs",
-    srcs = [
-        "//ts/lib:es6",
-    ],
     config_file = "//ts:rollup.config.js",
     entry_point = "bootstrap.ts",
     format = "iife",
@@ -87,6 +84,7 @@ rollup_bundle(
     sourcemap = "false",
     visibility = ["//visibility:public"],
     deps = [
+        "//ts/lib",
         "bootstrap",
         "@npm//@rollup/plugin-commonjs",
         "@npm//@rollup/plugin-node-resolve",

ts/lib/BUILD.bazel

@@ -41,12 +41,6 @@ ts_library(
     ],
 )
 
-filegroup(
-    name = "es6",
-    output_group = "es6_sources",
-    visibility = ["//visibility:public"],
-)
-
 # Tests
 ################