Narwhals v1.19.1

Changes

🚀 Performance improvements

• perf: avoid merge in pandas groupby (#1638)

✨ Enhancements

• feat: add collect schema to interchange dfs (#1646)
• feat: support std and var with ddof !=1 in pandas-like group by (#1645)
• feat: add DataFrame and LazyFrame explode method (#1542)

🐞 Bug fixes

• fix: Make compatible with latest cuDF release (#1640)

📖 Documentation

• docs: Note that maintains_order has no effect (but keep around for backwards-compatibility) (#1643)
• docs: fix typing example (#1637)
• docs: Use relative paths (#1636)
• docs: Remove warnings when building docs (#1631)
• docs: returns and arguments documentation for lazyframe class (#1630)
• docs: null handling (#1624)

🛠️ Other improvements

• chore: Update pyproject.toml (#1642)
• chore: register kwargs for CompliantExpr (#1614)
• fix: exclude protocols in api completeness script (#1635)
• test: not-so-old-versions, pretty-old-versions, nightlies (#1626)

Thank you to all our contributors for making this release possible!
@AlessandroMiola, @DeaMariaLeon, @Dhanunjaya-Elluri, @FBruzzesi, @MarcoGorelli, @marenwestermann and @marvinl803