[CT-1943] Loosen pin on `jsonschema` (via `hologram`)

[jtcohen6]

For more context on our latest thinking around dependencies (how & why we pin today, and how we want it to change):

• Revise our approach to pinning dependencies #6495

Summary

dbt-core depends on hologram, and as such it also includes hologram's transitive dependencies on jsonschema and python-dateutil. hologram's upper bound on jsonschema in particular is causing issues for some folks trying to install dbt-core alongside other popular tools, such as Airflow:

• Loosen dependency restriction to accept jsonschema 4.0 or better still, remove the upper bound hologram#52
• remove top pin for jsonschema hologram#51

Short term

• Try removing upper bound on jsonschema
• Release a new version of hologram with no / looser upper bound
• Support the new version of hologram in dbt-core

Medium term

Remove dbt-core's dependency on hologram entirely. It doesn't do nearly as much for us today as it used to, and the validation errors it raises aren't even all that nice.

• [CT-1944] [SPIKE] Remove dependency on hologram #6776

[emmyoop]

Part of this will be determining how to release hologram since we have not done that recently.

[r-richmond]

Is this targeted for being included with the 1.5 release?

[jtcohen6]

@r-richmond This hasn't been a top priority for us, compared to other planned work for v1.5, but I understand it's a pain for a number of folks who need to install dbt-core alongside other Python programs that require newer versions of jsonschema.

I just opened a quick PR to run CI with the latest version of jsonschema: #7219. If this "just works," we can try to sneak it in for v1.5.

Part of this will be determining how to release hologram since we have not done that recently.

@emmyoop I think it's just a manual release to PyPI.

[gshank]

I've released hologram 0.0.16