[jdk21u-dev] RFR: 8328953: JEditorPane.read throws ChangedCharSetException

[Martin Doerr]

Backport of [JDK-8328953](https://bugs.openjdk.org/browse/JDK-8328953). Clean except Copyright year change.

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Commit messages:
 - Backport 245514da51ef77757f530317e079a3f58370a0be

Changes: https://git.openjdk.org/jdk21u-dev/pull/637/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=637&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8328953
  Stats: 118 lines in 2 files changed: 92 ins; 16 del; 10 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/637.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/637/head:pull/637

PR: https://git.openjdk.org/jdk21u-dev/pull/637