Fix type-aware function parsing for functions with only optional arguments (#8189)

Account for functions with all optional parameters

Author: APickledWalrus

src/main/java/ch/njol/skript/lang/SkriptParser.java

@@ -1234,7 +1234,7 @@ record SignatureData(ClassInfo<?> classInfo, boolean plural) { }
 				boolean trySingle = false;
 				boolean trySinglePlural = false;
 				for (var signature : signatures) {
-					trySingle |= signature.getMinParameters() == 1 || signature.getMaxParameters() == 1;
+					trySingle |= signature.getMinParameters() <= 1 || signature.getMaxParameters() == 1;
 					trySinglePlural |= trySingle && !signature.getParameter(0).isSingleValue();
 					for (int i = 0; i < signature.getMaxParameters(); i++) {
 						if (signatureDatas.size() <= i) {

src/test/skript/tests/regressions/8187-functions behave wrong with all default args.sk

@@ -0,0 +1,7 @@
+local function test(x: number = 3, y: number = 5) returns number:
+	return {_x} + {_y}
+
+test "functions behave wrong with all default args":
+	assert test() is 8 with "no args did not use both default values"
+	assert test(1) is 6 with "only one arg did not use the second default value"
+	assert test(1, 2) is 3 with "both args still used a default value"