Fix intermittent IAM permission failures in delete-deployment command

[philasmar]

Description of changes:
Package Verifier Canary failed during SmokeTests execution (V1823700902)

Description of changes:

Fixed CloudFormation client initialization timing issue in DeleteDeploymentCommand

• Client was being created with wrong AWS credentials during constructor execution

• Removed the direct use of the CFN client and used the AWS Queryer service to query CFN

Testing

• Built successfully with dotnet build
• No existing unit tests directly instantiate DeleteDeploymentCommand
• Fix addresses the cross-account permission errors seen in smoke test logs

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[codecov]

Codecov Report

Attention: Patch coverage is 79.31034% with 6 lines in your changes missing coverage. Please review.

Project coverage is 62.11%. Comparing base (7aa80c4) to head (2a85af9).
Report is 2 commits behind head on dev.

Files with missing lines	Patch %	Lines
...CLI/ServerMode/Services/SessionAWSResourceQuery.cs	0.00%	4 Missing ⚠️
...AWS.Deploy.CLI/Commands/DeleteDeploymentCommand.cs	60.00%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##              dev     #959      +/-   ##
==========================================
- Coverage   62.14%   62.11%   -0.03%     
==========================================
  Files         294      294              
  Lines       10796    10813      +17     
  Branches     1616     1616              
==========================================
+ Hits         6709     6717       +8     
- Misses       3487     3494       +7     
- Partials      600      602       +2     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.