feat(precheck): add support for 3v3 templates

[htfab]

Notes:

• We could infer 3v3 projects either from the existence of a VAPWR port or from the different project area. But I think we can save ourselves from some surprises down the line if we make this choice explicit, so I've added an extra uses_3v3 field to info.yaml and use that as a single source of truth.
• For this version of the precheck I'm explicitly disallowing analog / custom gds projects with zero analog pins and access to 3v3 power. It might make sense to allow it in a follow-up patch if we can handle it properly.

[urish]

Thanks! I added uses_3v3 to the analog template. Can you please also update the https://tinytapeout.com/specs/analog/ with the new field?

For this version of the precheck I'm explicitly disallowing analog / custom gds projects with zero analog pins and access to 3v3 power. It might make sense to allow it in a follow-up patch if we can handle it properly.

What should change for handling it properly?

[htfab]

Thanks! I added uses_3v3 to the analog template. Can you please also update the https://tinytapeout.com/specs/analog/ with the new field?

Done.

For this version of the precheck I'm explicitly disallowing analog / custom gds projects with zero analog pins and access to 3v3 power. It might make sense to allow it in a follow-up patch if we can handle it properly.

What should change for handling it properly?

It depends whether we want to put it on a digital or an analog mux.

If we put it on a digital mux:

• do we need new def templates?
• do we need new power gate sizes?
• do we need to restrict available tile sizes for 3v3 custom gds projects?

If we put it on an analog mux:

• do we assume anywhere in our tools that analog_pins=0 implies digital?
• do we want to charge extra for limited real estate on the analog muxes?

[urish]

Thanks for explaining!