v1.15.0: Identities, Go 1.22

This version adds support for the Pebble Identities features (described in OP043), and updates the Go version when building binaries and Snaps from Go 1.20 to Go 1.22.

What's Changed

• feat(state): core of reading/writing identities in state by @benhoyt in #428
• feat(daemon): identities API endpoints by @benhoyt in #429
• feat(client): Go client for identities by @benhoyt in #430
• feat(cli): identities CLI commands by @benhoyt in #431
• fix(snap): build snap with Go 1.22 to fix CVE-2024-24790 by @cjdcordeiro in #448
• feat(daemon): use identities to auth API requests by @benhoyt in #434
• chore: use Go 1.22 (supported), in go.mod and binary builds by @benhoyt in #449

Full Changelog: v1.14.0...v1.15.0