Delete outdated docs.rs docs

- Remove "Developing without docker-compose"; it was highly outdated and
most of that information lives in the README now.
- Remove "Migrating to S3"; the command that uses was deleted over a
year ago and it wasn't very useful to anyone besides the docs.rs team
anyway.

Author: jyn514

src/SUMMARY.md

@@ -33,10 +33,8 @@
     - [Database maintenance](./crates-io/db-maintenance.md)
 - [docs.rs](./docs-rs/README.md)
   - [Adding dependencies to the build environment](./docs-rs/add-dependencies.md)
-  - [Developing without docker-compose](./docs-rs/no-docker-compose.md)
   - [Self-hosting a docs.rs instance](./docs-rs/self-hosting.md)
   - [Maintenance procedures](./docs-rs/maintenance.md)
-  - [Migrating from a local database to S3](./docs-rs/migrate-s3.md)
 - [Governance](./governance/README.md)
 - [Infrastructure](./infra/README.md)
     - [Other Installation Methods](./infra/other-installation-methods.md)