Bump UCAN spec version number to 1.0

[bdehaynin]

Description:

This milestone is part of the Fission Projects Roadmap.

Objectives:

• Officially shift the spec to 1.0.

ETA: 2023-10-02 (TBD)

Resources:

• Starmap
• UCAN working group
• UCAN documentation

Note: This milestone is subject to change as priorities and circumstances evolve.