RFR: 8267174: Many test files have the wrong Copyright header

[Erik Joelsson]

There are a number of files in the `test` directory that have an incorrect copyright header, which includes the "classpath" exception text. This patch removes that text from all test files that I could find it in. I did this using a combination of `sed` and `grep`. Reviewing this patch is probably easier using the raw patch file or a suitable webrev format.

It's my assumption that these headers were introduced by mistake as it's quite easy to copy the wrong template when creating new files.

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Commit messages:
 - JDK-8267174

Changes: https://git.openjdk.org/jdk/pull/15573/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15573&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8267174
  Stats: 1944 lines in 648 files changed: 0 ins; 1296 del; 648 mod
  Patch: https://git.openjdk.org/jdk/pull/15573.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15573/head:pull/15573

PR: https://git.openjdk.org/jdk/pull/15573