serverless: add support for pptx export

[viseshrp]

Closes #326

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 53.33333% with 14 lines in your changes missing coverage. Please review.

Project coverage is 80.43%. Comparing base (f71c77e) to head (73dd979).

Files with missing lines	Patch %	Lines
...ansys/dynamicreporting/core/serverless/template.py	25.00%	12 Missing ⚠️
src/ansys/dynamicreporting/core/serverless/adr.py	85.71%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #353      +/-   ##
==========================================
- Coverage   80.53%   80.43%   -0.11%     
==========================================
  Files          25       25              
  Lines        7163     7190      +27     
  Branches     1347     1351       +4     
==========================================
+ Hits         5769     5783      +14     
- Misses        976      989      +13     
  Partials      418      418              

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[Copilot]

Pull Request Overview

This PR adds support for exporting reports to PowerPoint (PPTX) format in the serverless dynamic reporting system. The implementation includes both template-level and ADR-level rendering methods for PPTX generation, along with comprehensive test coverage and documentation updates.

Key changes:

• Adds render_pptx() method to PPTXLayout template class for direct PPTX rendering
• Introduces render_report_as_pptx() method to the ADR singleton for convenient PPTX export
• Updates dependency specification for python-pptx to ensure compatibility

Reviewed Changes

Copilot reviewed 7 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/ansys/dynamicreporting/core/serverless/template.py	Adds render_pptx() method to PPTXLayout class and improves HTML rendering logic
src/ansys/dynamicreporting/core/serverless/adr.py	Implements render_report_as_pptx() method and adds validation for template loading
tests/serverless/test_adr.py	Adds comprehensive test coverage for PPTX rendering functionality
tests/serverless/test_template.py	Updates test variable names and enables previously disabled test
pyproject.toml	Pins python-pptx dependency to specific version for compatibility
doc/source/serverless/templates.rst	Documents PPTX rendering capabilities and usage examples
doc/source/serverless/instantiation.rst	Adds note about resource cleanup best practices

Comments suppressed due to low confidence (1)