Try a slightly newer date

2023-06-09 23:44:54 +05:30 · 2023-06-09 23:44:54 +05:30 · 3fb91c7f56
commit 3fb91c7f56
--- a/tests/r/r3.6-rspm/runtime.txt
+++ b/tests/r/r3.6-rspm/runtime.txt
@ -1 +1 @@
-r-3.6-2018-11-31
+r-3.6-2018-12-07