Fix backup all documentation

[realyota]

Changelog category (leave one):

• Documentation (changelog entry is not required)

Changelog entry (a user-readable short description of the changes that goes to CHANGELOG.md):

Fix backup all documentation (remove DATABASES keyword from BACKUP ALL). Fixes #58143.

Documentation entry for user-facing changes

• Documentation is written (mandatory for new features)

Information about CI checks: https://clickhouse.com/docs/en/development/continuous-integration/

Modify your CI run

NOTE: If your merge the PR with modified CI you MUST KNOW what you are doing
NOTE: Checked options will be applied if set before CI RunConfig/PrepareRunConfig step

Include tests (required builds will be added automatically):

• Fast test
• Integration Tests
• Stateless tests
• Stateful tests
• Unit tests
• Performance tests
• All with ASAN
• All with TSAN
• All with Analyzer
• All with Azure
• Add your option here

Exclude tests:

• Fast test
• Integration Tests
• Stateless tests
• Stateful tests
• Performance tests
• All with ASAN
• All with TSAN
• All with MSAN
• All with UBSAN
• All with Coverage
• All with Aarch64
• Add your option here

Extra options:

• do not test (only style check)
• disable merge-commit (no merge from master before tests)
• disable CI cache (job reuse)

Only specified batches in multi-batch jobs:

• 1
• 2
• 3
• 4

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[robot-ch-test-poll]

This is an automated comment for commit fb619ba with description of existing statuses. It's updated for the latest CI running

❌ Click here to open a full report in a separate page

Check name	Description	Status
A Sync	There's no description for the check yet, please add it to tests/ci/ci_config.py:CHECK_DESCRIPTIONS	⏳ pending
Mergeable Check	Checks if all other necessary checks are successful	❌ failure

Successful checks

Check name	Description	Status
CI running	A meta-check that indicates the running CI. Normally, it's in success or pending state. The failed status indicates some problems with the PR	✅ success
Docs check	Builds and tests the documentation	✅ success
PR Check	There's no description for the check yet, please add it to tests/ci/ci_config.py:CHECK_DESCRIPTIONS	✅ success
Style check	Runs a set of checks to keep the code style clean. If some of tests failed, see the related log from the report	✅ success