Integrated: Remove spurious ^ char from tarball name

[Athijegannathan Sundararajan]

backporting the same fix from jdk19

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Commit messages:
 - Remove spurious ^ char from tarball name

Changes: https://git.openjdk.org/jextract/pull/57/files
 Webrev: https://webrevs.openjdk.org/?repo=jextract&pr=57&range=00
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jextract/pull/57.diff
  Fetch: git fetch https://git.openjdk.org/jextract pull/57/head:pull/57

PR: https://git.openjdk.org/jextract/pull/57