Release v1.53.3

What's Changed

• Cache RefResolver subschemas lookup per instance by @sir-sigurd in #4590
• chore(deps): bump pyinstaller from 6.20.0 to 6.21.0 in /requirements by @dependabot[bot] in #4595
• chore(deps): bump setuptools from 82.0.1 to 83.0.0 in /requirements by @dependabot[bot] in #4593
• fix(E3701): Prevent false positive for Fn::If in OutputArtifacts Name by @kddejong in #4596
• fix(schema): Add file locking to prevent concurrent cache corruption by @kddejong in #4598
• Update CloudFormation schemas to 2026-07-28 by @github-actions[bot] in #4589

Full Changelog: v1.53.2...v1.53.3