fix: Validate spill read schema

[2010YOUY01]

Which issue does this PR close?

• Closes #.

Rationale for this change

Follow-up to a review comment in : #21713 (comment)
Not a bug fix, this PR tries to be more defensive and catch potential bugs.

Before, when you write a spill file from a SpillManager, then read with another SpillManager of different schema, it would succeed. This is not a expected use pattern, an error will get propagated to the caller, and become harder to debug.

This PR validates the schema when reading the first batch, and fail fast if the schema does not match.

Note it only validates the schema, if two SpillManagers with the same schema do read and write, it's still allowed, but this is not a expected use pattern. Validating this case requires assigning SpillManager UID, and add that to the Arrow IPC file metadata, can be tricky, so leave this as TODO for simplicity.

What changes are included in this PR?

Are these changes tested?

UTs

Are there any user-facing changes?

No

[comphead]

Suggested change

	return Err(exec_datafusion_err!(
	"Spill file schema mismatch: expected {}, got {}. \
	The caller must use the same SpillManager that created the spill file to read it.",
	expected_schema,
	actual_schema
	));
	return exec_err!(
	"Spill file schema mismatch: expected {}, got {}. \
	The caller must use the same SpillManager that created the spill file to read it.",
	expected_schema,
	actual_schema
	);

[comphead]

Thanks @2010YOUY01 makes sense