[🐸 Frogbot] Update version of github.com/sigstore/timestamp-authority/v2 to 2.0.6

[github-actions]

📦 Vulnerable Dependencies

Severity	ID	Contextual Analysis	Direct Dependencies	Impacted Dependency	Fixed Versions
Medium	CVE-2026-39984	Not Covered	github.com/jfrog/jfrog-cli-evidence:v0.9.0 github.com/sigstore/timestamp-authority/v2:v2.0.5	github.com/sigstore/timestamp-authority/v2 v2.0.5	[2.0.6]

🔖 Details

Vulnerability Details

Contextual Analysis:	Not Covered
Direct Dependencies:	github.com/jfrog/jfrog-cli-evidence:v0.9.0, github.com/sigstore/timestamp-authority/v2:v2.0.5
Impacted Dependency:	github.com/sigstore/timestamp-authority/v2:v2.0.5
Fixed Versions:	[2.0.6]
CVSS V3:	5.5

Sigstore Timestamp Authority has Improper Certificate Validation in verifier

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🐸 JFrog Frogbot