[jdk8u-dev] RFR: 8254318: Remove .hgtags

[George Adams]

Removes unused .hgtags files after the Git move. No code change. Low risk

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Commit messages:
 - Backport 62a7f5d3236ab2248518a475b1d8b71cb4bf1313

Changes: https://git.openjdk.org/jdk8u-dev/pull/108/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=108&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8254318
  Stats: 10233 lines in 9 files changed: 0 ins; 10233 del; 0 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/108.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev pull/108/head:pull/108

PR: https://git.openjdk.org/jdk8u-dev/pull/108