Stop removing nodes in maintenance from in replacement set

[hgreebe]

Description of changes

• Stop removing nodes in maintenance from in replacement set
• Resolve bug where static nodes instance replacement fails when node is in a user created maintenance reservation
• Does not remove nodes in maintenance from nodes_still_in_replacement
• Nodes in maintenance will still wait the replacement timeout window before they are deemed unhealthy

Tests

• Ran:

test-suites:
  schedulers:
    test_slurm.py::test_slurm_maintenance_reservation:
      dimensions:
        - regions: ["us-east-1"]
          instances: {{ common.INSTANCES_DEFAULT_X86 }}
          oss: ["alinux2023"]
          schedulers: ["slurm"]

References

*Bug originally introduced in this PR: #591

Please review the guidelines for contributing and Pull Request Instructions.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.