[SYCL-MLIR][sycl-constant-propagation] Fix `getConstantArgs` lambda (#10690)
Avoid lambda outliving captured values:
- Pass `symbolTable` by reference and capture by reference in lambda
instead of defining in function body to avoid errors when it goes out of
scope;
- Capture `op` by value;
- Init-capture `isConstant`
- Drop default capture and add comment explaining why
This change enables use of `llvm::make_filter_range` so no filtering
needs to be done when using the range.
Signed-off-by: Victor Perez <victor.perez@codeplay.com>