RFR: 8339524: Clean up a few ExtendedRobot tests [v4]

[Alisen Chung]

> Cleaning up tests building ExtendedRobot that shouldn't be.

Alisen Chung has updated the pull request incrementally with one additional commit since the last revision:

  readd ER

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/20846/files
  - new: https://git.openjdk.org/jdk/pull/20846/files/04eec257..50b582c0

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20846&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20846&range=02-03

  Stats: 7 lines in 1 file changed: 1 ins; 1 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/20846.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20846/head:pull/20846

PR: https://git.openjdk.org/jdk/pull/20846