[SYCL][E2E] Temporarily disable reduction test execution (#19892)

Failing sporadically on basically all platforms and OSs.

#19680
#19767

Signed-off-by: Sarnie, Nick <[email protected]>

Author: sarnex

sycl/test-e2e/Reduction/lit.local.cfg

@@ -0,0 +1,4 @@
+# https://github.com/intel/llvm/issues/19680
+# https://github.com/intel/llvm/issues/19767
+if 'run-mode' in config.available_features:
+  config.unsupported_features += ['true']