WHPG 7.6 release

[mpfuster]

No description provided.

[linwen]

Reviewed against the 7.6.0-WHPG tag (139 commits since 7.5.0-WHPG). The Critical security block and the "Applying the file function privilege fix" section, the whpg_dispatch_topology_file/_state entries, the pg_stat_operations classnames, DISTRIBUTED COORDINATOR ONLY, the --restrict-key and \restrict/\unrestrict descriptions, the CREATE/ALTER OPERATOR note, gp_toolkit 1.9, all 23 CVE entries, the bug-fix/new-feature/enhancement lists and every cross-file link target check out. Two things should be fixed before merging: the pgcrypto option name (two places) and the note-container syntax in platform-requirements.md; the rest are wording suggestions.

[linwen]

Re-reviewed after the "Address Linwen's feedback" commit. All 7 earlier comments are correctly addressed. One new issue was introduced by that same commit, on a line I had not flagged (it was already accurate) — see inline.

[linwen]

Looks good to me.