RUN-3992 Improve docs about Aws ssm timeout

[Jesus-Osuna-M]

Description
Updates AWS SSM documentation to reflect configurable execution timeout feature https://github.com/rundeckpro/rundeckpro/pull/4537
This PR updates the AWS Systems Manager (SSM) Node Executor documentation to include the new configurable timeout functionality introduced in version 5.18.0.

Changes Made:

• Added clarity on different timeout limits based on authentication method
• With Assume Role: up to 12 hours (43200 seconds)
• Without Assume Role: up to 48 hours (172800 seconds)
• Inline Scripts (RBA/RBA-SH): maximum 8 hours (28800 seconds)
• Added best practice guidance for configuring timeouts with safety margins
• Documented all configuration methods: project-wide, node source level, project config file, and node level
• Included important warnings about IAM policies and AWS service limits
• Added cross-reference to extended execution time capabilities
• Linked to detailed timeout configuration documentation

[Copilot]

Pull request overview

This pull request significantly improves the AWS SSM timeout documentation by expanding it from a brief configuration note into a comprehensive guide. The changes clarify timeout limits based on different authentication methods and execution types, provide better-organized configuration instructions, and add helpful best practices for timeout management.

Key Changes:

• Added detailed timeout limits documentation including authentication-specific maximums (12 hours with Assume Role, 48 hours without, 8 hours for inline scripts)
• Restructured configuration instructions into four clear methods with code block examples
• Added VuePress admonitions for important warnings and best practices about timeout configuration
• Cross-referenced the enhanced documentation from the cross-account AWS SSM tutorial

Reviewed changes

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

File	Description
docs/manual/projects/node-execution/aws-ssm.md	Expanded the "Execution Timeout Configuration" section with detailed limits, structured configuration methods using code blocks, and added warning/tip admonitions for best practices
docs/learning/howto/cross-account-aws-ssm.md	Added a tip box referencing the enhanced timeout documentation with a quick summary of timeout limits

[fdevans]

this is a good update. Let's review the CoPilot comments about the timeout values.