RFR: 8306329 : Update ICU4C to 73 [v2]

[Hima Bindu Meda]

> Updated ICU to v73.1. Verified build and sanity. No issues seen.

Hima Bindu Meda has updated the pull request incrementally with one additional commit since the last revision:

  update copyright year

-------------

Changes:
  - all: https://git.openjdk.org/jfx/pull/1138/files
  - new: https://git.openjdk.org/jfx/pull/1138/files/599b7523..096c4d39

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1138&range=01
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1138&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jfx/pull/1138.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1138/head:pull/1138

PR: https://git.openjdk.org/jfx/pull/1138