Guards: bound implicit return SSA filtering

Use an empty default for relevantImplicitReturnSsaDefinition instead of the Cartesian product. Languages supporting implicit returns must provide a bounded implementation; Go already does.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: owen-mc

java/ql/lib/semmle/code/java/controlflow/Guards.qll

@@ -351,7 +351,7 @@ private module LogicInput_v3 implements GuardsImpl::LogicInputSig {
   predicate relevantImplicitReturnSsaDefinition(
     GuardsInput::NonOverridableMethod method, SsaDefinition def
   ) {
-    any()
+    none()
   }
 
   predicate rangeGuard(GuardsImpl::PreGuard guard, GuardValue val, Expr e, int k, boolean upper) {

shared/controlflow/codeql/controlflow/Guards.qll

@@ -618,7 +618,7 @@ module Make<
     default predicate relevantImplicitReturnSsaDefinition(
       NonOverridableMethod method, SsaDefinition def
     ) {
-      any()
+      none()
     }
 
     /**