Check if symbol is static before calling SYM2ID on it

It occurs to me that if a symbol is dynamic, we were causing it to
become a static symbol (e.g. making it never be able to be garbage
collected).

This can be very bad! And also, we know the symbol we're looking for
must be a static symbol because if nothing else, our initialization
caused it to become a static symbol.

Thus, if we see a dynamic symbol, we can stop there, since by
definition it won't be the symbol we're looking after.

This is... really awkward to add a specific unit test for, so
I've just relied on our existing test coverage to show that this
has not affected the correctness of our otel code.

ext/datadog_profiling_native_extension/collectors_thread_context.c

@@ -1750,7 +1750,7 @@ static void otel_without_ddtrace_trace_identifiers_for(
 
   VALUE root_span_type = rb_ivar_get(local_root_span.span, at_kind_id /* @kind */);
   // We filter out spans that don't have `kind: :server`
-  if (root_span_type == Qnil || !RB_TYPE_P(root_span_type, T_SYMBOL) || SYM2ID(root_span_type) != server_id) return;
+  if (root_span_type == Qnil || !RB_TYPE_P(root_span_type, T_SYMBOL) || !RB_STATIC_SYM_P(root_span_type) || SYM2ID(root_span_type) != server_id) return;
 
   VALUE trace_resource = rb_ivar_get(local_root_span.span, at_name_id /* @name */);
   if (!RB_TYPE_P(trace_resource, T_STRING)) return;