docs(snix/docs/TODO): drop builder TODOs

A mention of these different builders is included in the a footnote
in the documentation, and various issues for the different TODOs were
created:

 - #128 Implement bwrap-based Builder
 - #129 Implement gVisor-based builder
 - #130 Implement Cloud Hypervisor-based builder
 - #131 OCI builder: add preflight checks
 - #132 BuildService: refactor to be more granular

Change-Id: I349b799e233ba8bef39a139cf2453d3214bb69b3
Reviewed-on: https://cl.snix.dev/c/snix/+/30474
Autosubmit: Florian Klink <flokli@flokli.de>
Tested-by: besadii
Reviewed-by: Jonas Chevalier <zimbatm@zimbatm.com>

snix/docs/src/TODO.md

@@ -70,26 +70,6 @@ Extend the other pages in here. Some ideas on what should be tackled:
    is probably still not too clear.
  - Absorb the rest of //snix/website into this.
 
-### Builders
-Once builds are proven to work with real-world builds, and the corner cases
-there are ruled out, adding other types of builders might be interesting.
-
- - bwrap
- - gVisor
- - Cloud Hypervisor (using similar technique as `//snix//boot`).
-
-Long-term, we want to extend traits and gRPC protocol.
-This requires some more designing. Some goals:
-
- - (more granular) control while a build is happening
- - expose more telemetry and logs
-
- - Add pre-flight checks in the OCI builder:
-   - ensure `fusermount` suid binary exists
-   - ensure `allow_other` is set
-   - ensure `runc` exists in `$PATH`
-
-
 ### Store composition
  - Combinators: list-by-priority, first-come-first-serve, cache
  - Store composition hierarchies (@yuka).