RFR: 8371759: Add missing @Override annotations in com.sun.imageio package

[Sergey Bylokhov]

This patch adds missing `@Override` annotations to methods in the `com.sun.imageio` package that override methods from a superclass or interface.
Only source annotations are added; there are no behavioral changes.

The previous patch for `com.sun.beans` can be found here: https://github.com/openjdk/jdk/pull/27887.

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Commit messages:
 - 8371759: Add missing @Override annotations in com.sun.imageio package

Changes: https://git.openjdk.org/jdk/pull/28282/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28282&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8371759
  Stats: 491 lines in 93 files changed: 401 ins; 0 del; 90 mod
  Patch: https://git.openjdk.org/jdk/pull/28282.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28282/head:pull/28282

PR: https://git.openjdk.org/jdk/pull/28282