Do not assume admin privileges on keystone

[enolfc]

Description

Avoid issues when running cASO with a low privileges account that cannot
list all projects and scope the tokens to the projects that are to be
accounted. This allows to run cASO and generate records for non-admin
users.

Fixes #124

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide
instructions so we can reproduce. Please also list any relevant details for
your test configuration

• Test caso-extract using v3oidcaccesstoken authentication with an EGI Check-in access token in 2 projects at IFCA-LCG2. Configuration:

  [DEFAULT]
  spooldir = var/spool/caso
  site_name = IFCA-LCG2
  projects = 999f045cb1ff4684a15ebb338af69460, 5eb8959a799240a98f4f303f5fbd80be
  [accelerator]
  [benchmark]
  [keystone_auth]
  auth_type = v3oidcaccesstoken
  auth_url = https://api.cloud.ifca.es:5000/v3
  project_id = 999f045cb1ff4684a15ebb338af69460
  identity_provider = egi.eu
  protocol = openid
  access_token = XXX-redacted
  [logstash]
  [sample_remote_file_source]
  [ssm]
  

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[enolfc]

Tests seems broken but not due to this code :(

[alvarolopez]

@enolfc this is due to the Pydantic version, can you rebase on top of https://github.com/IFCA-Advanced-Computing/caso/tree/pydantic2 ?