Speed up the test suite

[iskandr]

Summary

• replace whole-release pyensembl materialization with bounded, cached exact-ID lookups
• cap cosmetic scatter-label adjustment and keep plot tests on one xdist worker to reuse Matplotlib state
• avoid a duplicate released CMN shard parse, report slow tests in local/CI runs, and remove duplicate deploy linting
• bump the code-only package version to 1.8.172; data versions are unchanged

Measured result

• comparable no-coverage suite: 69.3s before, 44.0s after (36% lower wall time)
• coverage suite: 1,037 passed, 0 skipped in 62.8s before adding the three dependency-free resolver regressions
• transcript resolver test: 16.8s before, 0.01s after

Verification

• ./test.sh
• focused resolver/workflow tests: 18 passed
• ./lint.sh
• bash -n test.sh deploy.sh