Clarify PEcAn.SIPNET dependency in uncertainty.qmd

[shreyannandanwar]

Description

Refers to commit #3734 .
This PR clarifies a missing dependency in the uncertainty.qmd Basic Run tutorial by explicitly documenting the requirement for the PEcAn.SIPNET package. Without this clarification, users may encounter errors when running the demo without understanding the cause.

##Changes

• Included the installation command for PEcAn.SIPNET as inline documentation (without adding it as an executable code chunk)
• added Note to the uncertainty.qmd

Review Time Estimate

• Immediately
• Within one week
• When possible

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My change requires a change to the documentation.
• My name is in the list of CITATION.cff
• I agree that PEcAn Project may distribute my contribution under any or all of
  • the same license as the existing code,
  • and/or the BSD 3-clause license.
• I have updated the CHANGELOG.md.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[infotroph]

If you're like me thinking "didn't we just merge this in #3734?": No, that was for the basic run and this is for the uncertainty demo.

Suggestion merged