[release] version 1.4.0

[gchan]

Description

Bump version to 1.4.0 for release.

Changes since v1.3.1

• Fix subtest handling: propagate subtest failures to the parent test result instead of letting SubtestReport objects overwrite it (fix: prevent SubtestReport from overwriting parent test result #94)
• Bump cryptography from 45.0.5 to 46.0.5 (build(deps): bump cryptography from 45.0.5 to 46.0.5 #92)
• Add pytest 9.x CI matrix entry so subtest integration tests are exercised ([TE-5274] Add pytest 9.x CI matrix entry for subtest integration tests #95)

Context

Resolves TE-5388

Verification

All tests pass.

Deployment

Low risk. The Buildkite release pipeline will automatically publish to PyPI after merge.

[pda]

Just fixes might warrant v1.3.2 instead of v1.4.0 but I don't think it matters terribly.

[gchan]

Just fixes might warrant v1.3.2 instead of v1.4.0 but I don't think it matters terribly.

Yeah I was on the fence. You could argue this is a fix but it's a slight behaviour change (which folks may have relied upon) so leaned towards a minor version bump.