RFR: 8315960: test/jdk/java/io/File/TempDirDoesNotExist.java leaves test files behind [v4]

[Brian Burkhalter]

> Add a `finally` block to delete the created files.

Brian Burkhalter has updated the pull request incrementally with one additional commit since the last revision:

  8315960: Remove vestigial unused import

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Changes:
  - all: https://git.openjdk.org/jdk/pull/15757/files
  - new: https://git.openjdk.org/jdk/pull/15757/files/2d444213..f940caed

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15757&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15757&range=02-03

  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/15757.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15757/head:pull/15757

PR: https://git.openjdk.org/jdk/pull/15757