packit: Drop obsolete sandcastle hack

Since commit 9d4c08ff2a, SRPM builds happen in COPR, so we can drop the
sandcastle hack.

Also drop the duplicated `post-upstream-clone` key.

packit.yaml

@@ -7,21 +7,12 @@ srpm_build_deps:
 - make
 - npm
 actions:
-  post-upstream-clone:
   post-upstream-clone:
     - make cockpit-starter-kit.spec
     # replace Source1 manually, as create-archive: can't handle multiple tarballs
     - make node-cache
     - sh -c 'sed -i "/^Source1:/ s/https:.*/$(ls *-node*.tar.xz)/" cockpit-*.spec'
-  # build in development mode; production mode uses too much memory for limited
-  # sandcastle containers; also reduce memory consumption of webpack
-  # https://github.com/packit/sandcastle/pull/92
-  # https://medium.com/the-node-js-collection/node-js-memory-management-in-container-environments-7eb8409a74e8
-  create-archive:
-    - make NODE_ENV=development NODE_OPTIONS=--max-old-space-size=500
-    # dummy LICENSE.txt, as terser did not run
-    - touch dist/index.js.LICENSE.txt.gz
-    - make dist
+  create-archive: make dist
   # starter-kit.git has no release tags; your project can drop this once you have a release
   get-current-version: make print-version
 jobs: