x265: add workaround for CMake 4

[carlocab]

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Fixes Homebrew/discussions#6088

[carlocab]

Needs fixed upstream.

[cho-m]

• https://bitbucket.org/multicoreware/x265_git/commits/b354c009a60bcd6d7fc04014e200a1ee9c45c167
• https://bitbucket.org/multicoreware/x265_git/commits/51ae8e922bcc4586ad4710812072289af91492a8

May need to check if any others