Serialize Python requests for tools as canonicalized strings (#14109)
When working on support for reading global Python pins in tool
operations, I noticed that we weren't using the canonicalized Python
request in receipts — we were using the raw string provided by the user.
Since we'll need to compare these values, we should be using the
canonicalized string.
The `Tool` and `ToolReceipt` types have been updated to hold a
`PythonRequest` instead of a `String`, and `Serialize` was implemented
for `PythonRequest` so canonicalization can happen at the edge instead
of being the caller's responsibility.
uv
47c522f9 - Serialize Python requests for tools as canonicalized strings (#14109)
