[full-ci] chore: update reva to v2.26.6

[micbar]

Description

• Bugfix cs3org/reva#4955: Allow small clock skew in reva token validation
• Bugfix cs3org/reva#4929: Fix flaky posixfs integration tests
• Bugfix cs3org/reva#4953: Avoid gateway panics
• Bugfix cs3org/reva#4959: Fix missing file touched event
• Bugfix cs3org/reva#4933: Fix federated sharing when using an external identity provider
• Bugfix cs3org/reva#4935: Enable datatx log
• Bugfix cs3org/reva#4936: Do not delete mlock files
• Bugfix cs3org/reva#4954: Prevent a panic when logging an error
• Bugfix cs3org/reva#4956: Improve posixfs error handling and logging
• Bugfix cs3org/reva#4951: Pass the initialized logger down the stack

Related Issue

• Fixes <issue_link>

Motivation and Context

How Has This Been Tested?

• test environment:
• test case 1:
• test case 2:
• ...

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Technical debt
• Tests only (no source changes)

Checklist:

• Code changes
• Unit tests added
• Acceptance tests added
• Documentation ticket raised:

[ScharfViktor]

app-provider e2e tests are green https://drone.owncloud.com/owncloud/web/49107/15/14

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud