Remove "resource" package from DEPS.

As I was fixing up old references to "dartfmt", I noticed the resource
package is marked archived. It doesn't seem to be used anywhere in the
SDK, so can we remove it?

Change-Id: I9a2230c6f8c42c446e7d2576a8d26f8d06e0cfb0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/215157
Auto-Submit: Bob Nystrom <rnystrom@google.com>
Commit-Queue: Bob Nystrom <rnystrom@google.com>
Reviewed-by: Lasse R.H. Nielsen <lrn@google.com>

.dart_tool/package_config.json

@@ -11,7 +11,7 @@
     "constraint, update this by running tools/generate_package_config.dart."
   ],
   "configVersion": 2,
-  "generated": "2021-10-03T09:32:39.517171",
+  "generated": "2021-10-04T10:29:25.433041",
   "generator": "tools/generate_package_config.dart",
   "packages": [
     {
@@ -565,12 +565,6 @@
       "packageUri": "lib/",
       "languageVersion": "2.12"
     },
-    {
-      "name": "resource",
-      "rootUri": "../third_party/pkg/resource",
-      "packageUri": "lib/",
-      "languageVersion": "2.0"
-    },
     {
       "name": "scrape",
       "rootUri": "../pkg/scrape",