<i18n dev> RFR: 8365180: Remove sun.awt.windows.WInputMethod.finalize()

[Phil Race]

Remove finalize() from WInputMethod.java - it is used to free a native id.
Also the reason dispose() didn't free it seems no longer relevant.
Although I did see (when instrumenting) that dispose() was called when I disposed() the Frame referencing the IM,
I don't know if I can be sure that is always done. So safest to add the Disposer in case it isn't.

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

Commit messages:
 - 8365180

Changes: https://git.openjdk.org/jdk/pull/26706/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26706&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8365180
  Stats: 28 lines in 2 files changed: 12 ins; 3 del; 13 mod
  Patch: https://git.openjdk.org/jdk/pull/26706.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26706/head:pull/26706

PR: https://git.openjdk.org/jdk/pull/26706