RFR: 8364673: Remove duplicate font mapping for itcavantgarde in psfontj2d.properties

[Phil Race]

I've spent some time trying to think if one of these was supposed to be something else, but it looks like a dup.

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Commit messages:
 - 8364673

Changes: https://git.openjdk.org/jdk/pull/27784/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27784&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8364673
  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/27784.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27784/head:pull/27784

PR: https://git.openjdk.org/jdk/pull/27784