Correct PraisonAI A2A fixed version

[cookesan]

Corrects PraisonAI A2A fixed version in GHSA-vg22-4gmj-prxw.

Audit refresh, July 8, 2026:

• Confirmed the live PR is open, ready for review, merge-clean, and the visible advisory check is green.
• Rechecked the merge-base diff: exactly one advisory JSON file changes (advisories/github-reviewed/2026/05/GHSA-vg22-4gmj-prxw/GHSA-vg22-4gmj-prxw.json), JSON parses, git diff --check passes, and the exact-head worktree is clean.
• Revalidated the added public references and package-version evidence in the diff; all resolve through their source site or registry.

[cookesan]

Rechecked this PR while keeping the open Advisory Database queue current.

• The patch updates the PraisonAI fixed version from 4.6.40 to 4.6.51 and updates last_known_affected_version_range to <= 4.6.50.
• PraisonAI version 4.6.51 exists on PyPI, and the GitHub release tag resolves as v4.6.51.
• The added commit resolves to e0fb8e7dd1ee6759c18ed07f436c21dbd9c20747 with the subject fix: harden JWT secret handling and replace eval() in examples (#1793).

The head advisory JSON validates against the OSV schema.