Update QuantConnect.pythonnet to 2.0.65

[jhonabreul]

Description

Updates the QuantConnect.pythonnet package reference to 2.0.65 in the 11 csproj files that consume it.

2.0.65 makes .NET DateTime values converted to Python support subtraction and ordering against pure datetime.date operands (coerced via the datetime's date part), removing the unsupported operand type(s) for -: 'datetime.datetime' and 'datetime.date' / can't compare datetime.datetime to datetime.date failures from user algorithms' DTE-style math: QuantConnect/pythonnet#143.

Do not merge until QuantConnect/pythonnet#143 is merged and 2.0.65 is indexed on NuGet — restore fails before then. Companion (no merge-order dependency): #9659 improves the error messages for the datetime/date mixes pythonnet cannot coerce.

Related Issue

N/A

Motivation and Context

DTE filtering ((contract.id.date - self.time.date()).days) is the most repeated runtime arithmetic failure in user Python algorithms; 2.0.65 removes it.

Requires Documentation Change

No

How Has This Been Tested?

• With the 2.0.65 Python.Runtime.dll injected over Lean's test output (mirroring pythonnet's Lean CI workflows): Python unit tests 16045 passed / 0 failed / 9 skipped; Python regression algorithms 324/324 passed.

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)
• Non-functional change (xml comments/documentation/etc)

Checklist:

• My code follows the code style of this project.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[jhonabreul]

Superseded: the version bump moved into #9659 alongside the datetime/date error-message improvements.