[Test] Limit the DescribeInstanceType API to get 100 instances for filtering

[himani2411]

Description of changes

• Limit the DescribeInstanceType API to get 100 instances for filtering based on max constraint https://docs.aws.amazon.com/cli/latest/reference/ec2/describe-instance-types.html
• Use data structures which will handle duplicates automatically
• Remove redundant calls to DescribeInstanceType

Tests

• PASSED

test-suites:
  basic:
    test_essential_features.py::test_essential_features:
      dimensions:
        - regions: [{{ US_EAST_1_INSTANCE_TYPE_0_xlarge_CAPACITY_RESERVATION_8_INSTANCES_2_HOURS_NOPG_OS_X86_1 }}]
          instances: [{{ US_EAST_1_INSTANCE_TYPE_0 }}.xlarge]
          oss: [{{ DCV_OS_X86_1 }}]
          schedulers: ["slurm"]
  health_checks:
    test_gpu_health_checks.py::test_cluster_with_gpu_health_checks:
      dimensions:
        - regions: [{{ US_WEST_2_GPU_INSTANCE_TYPE_0_CAPACITY_RESERVATION_3_INSTANCES_2_HOURS_NOPG_OS_X86_5 }}]
          instances: [{{ US_WEST_2_GPU_INSTANCE_TYPE_0 }}]
          oss: [{{ OS_X86_5 }}]
          schedulers: ["slurm"]

References

• Link to impacted open issues.
• Link to related PRs in other packages (i.e. cookbook, node).
• Link to documentation useful to understand the changes.

Checklist

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

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.18%. Comparing base (820e0d9) to head (2e79439).
⚠️ Report is 35 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #7181   +/-   ##
========================================
  Coverage    90.18%   90.18%           
========================================
  Files          183      183           
  Lines        16565    16565           
========================================
  Hits         14939    14939           
  Misses        1626     1626           

Flag	Coverage Δ
unittests	90.18% <ø> (ø)

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[hehe7318]

Are we sure only p/g types are GPU instance? What about trn instances?

[himani2411]

Trn has NeuronInfo instead of GPuInfo, which describe's the in-house inference chip we create.

for GPU so far I have found only these p and g family

• https://docs.aws.amazon.com/dlami/latest/devguide/gpu.html
• https://www.vantage.sh/blog/aws-ec2-gpu-instances-g-family-vs-p-family-g4dn