Set version to v1.0.1

Signed-off-by: Harmen Stoppels <[email protected]>

Backports v1.0.0 (spack#50798)

* Pin builtin repo to releases/v2025.07
* Add `CHANGELOG.md` and bump version to `1.0.0`

This also includes release notes from 0.23 that were never brought onto `develop`.

---------

Signed-off-by: Gregory Becker <[email protected]>
Signed-off-by: Harmen Stoppels <[email protected]>
Signed-off-by: Todd Gamblin <[email protected]>
Co-authored-by: Gregory Becker <[email protected]>
Co-authored-by: Todd Gamblin <[email protected]>

Snapshot release 2025-07-06

Snapshot release 2025-06-29

Snapshot release 2025-06-22

Reverted some false merge remnants

merged v.0.23.1 into imgw

Snapshot release 2025-06-15

Snapshot release 2025-06-08

Snapshot release 2025-06-01