v0.4.0

What's Changed

• feat: improve tracing when failing to retrieve a host block by @prestwich in #141
• refactor: remove bogus await from env task by @prestwich in #146
• refactor: move pre host fetching to the env task by @prestwich in #147
• feat(config): Set SlotCalculator config with CHAIN_NAME instead of verbose values by @Evalir in #148
• chore(config): fallback to FromEnv for the SlotCalculator instead of using FromEnvVar by @Evalir in #149
• chore(readme): fixes by @Evalir in #150
• refactor: pull submit logic into builder_helper module by @dylanlott in #142
• config: adds flashbots endpoint env var by @dylanlott in #143
• chore: pass block-associated span with simenv and simresult by @prestwich in #151
• feat: span the provider send spawns by @prestwich in #152
• feat: add span to slot still valid by @prestwich in #153
• feature: adds Flashbots submit task by @dylanlott in #144
• feat: add host txns to builder bundle by @prestwich in #156

Full Changelog: v0.3.0...v0.4.0