1.20.0

• [BUGFIX] Support standing up a FileDataContext on a read-only filesystem (#12000)
• [BUGFIX] Narrow single-pass column_values.unique on SQLAlchemy (Redshift WLM) (#11863) (thanks @leodrivera)
• [BUGFIX] deduplicate sql metric aliases to prevent view schema collisions (#10926) (#11905) (thanks @TemidayoA)
• [BUGFIX] Report an unmet expectation when a column has no quantiles (#12026)
• [BUGFIX] Exclude nulls and fix the rank offset in the SQLite quantile metric (#12008) (thanks @SreeramaYeshwanthGowd)
• [MAINTENANCE] Explain why a not-ready issue can't be self-claimed (#11999)
• [MAINTENANCE] Bump postcss from 8.5.12 to 8.5.25 in /docs/docusaurus (#12013)
• [MAINTENANCE] Bump brace-expansion from 1.1.16 to 1.1.18 in /docs/docusaurus (#12014)
• [MAINTENANCE] Namespace ephemeral SQL test schemas under gx_ci_test_ and fix cleanup regex charsets (#12015)
• [MAINTENANCE] Bump fast-uri from 3.1.4 to 3.1.5 in /docs/docusaurus (#12019)
• [MAINTENANCE] Defer the schema listing in TableAsset.test_connection to the failure path (#12020)
• [MAINTENANCE] BigQuery CI (#12016)
• [CONTRIB] Promote ExpectColumnValuesToMatchStrftimeFormat to supported-core (#12009) (thanks @nanjeshramesh)