RFR: 8305794: Unused interface sun.security.util.PermissionFactory can be removed

[Kevin Driver]

All known implementors of this interface were removed in [JDK-8029886](https://bugs.openjdk.org/browse/JDK-8029886).

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Commit messages:
 - removed unused interface

Changes: https://git.openjdk.org/jdk/pull/13464/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13464&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8305794
  Stats: 36 lines in 1 file changed: 0 ins; 36 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/13464.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13464/head:pull/13464

PR: https://git.openjdk.org/jdk/pull/13464