RFR: Merge openjdk/jdk21u:master

[William Kemper]

Merges tag jdk-21.0.8-ga

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Commit messages:
 - 8361672: [21u] Remove designator DEFAULT_PROMOTED_VERSION_PRE=ea for release 21.0.8
 - 8360147: Better Glyph drawing redux
 - 8350991: Improve HTTP client header handling
 - 8349594: Enhance TLS protocol support
 - 8349111: Enhance Swing supports
 - 8348989: Better Glyph drawing
 - 8345625: Better HTTP connections

The merge commit only contains trivial merges, so no merge-specific webrevs have been generated.

Changes: https://git.openjdk.org/shenandoah-jdk21u/pull/207/files
  Stats: 303 lines in 19 files changed: 217 ins; 22 del; 64 mod
  Patch: https://git.openjdk.org/shenandoah-jdk21u/pull/207.diff
  Fetch: git fetch https://git.openjdk.org/shenandoah-jdk21u.git pull/207/head:pull/207

PR: https://git.openjdk.org/shenandoah-jdk21u/pull/207