[TraceQL] Arbitrary math with static values and attributes does not work

[joe-elliott]

Describe the bug

Queries like the following will fail:

{span.http.status_code + 100 > 3}

with an error like:

unknown operation. condition: {Attribute:span.http.status_code Op:+ Operands:[100]}

The issue is that the engine creates the bad condition here:

tempo/pkg/traceql/ast_conditions.go

Line 54 in f34a137

request.appendCondition(Condition{

and the fetch layer rejects it here while trying to build a predicate:

tempo/tempodb/encoding/vparquet3/block_traceql.go

Line 602 in f34a137

return fmt.Errorf("unknown operation. condition: %+v", cond)

There are a couple of fixes, but the most straightforward one would be to produce an OpNone condition in the engine asking for the span.http.status_code field.