test: Remove intermittent and presumed fixed tsan race suppressions

LoadWallet was added in commit d77170d526, which
points to a traceback with BerkeleyBatch in it. Now that BDB is removed,
this can be removed as well.

The race in DatabaseBatch was added in commit
fd59670642, which does not point to a
traceback. This was likely also fixed with the BDB removal.

If not, the suppressions should be added back, mentioning that they are
intermittent and including a traceback and possibly steps to reproduce.

test/sanitizer_suppressions/tsan

@@ -3,10 +3,6 @@
 #
 # https://github.com/google/sanitizers/wiki/ThreadSanitizerSuppressions
 
-# race (TODO fix)
-race:LoadWallet
-race:DatabaseBatch
-
 # deadlock (TODO fix)
 # To reproduce, see:
 # https://github.com/bitcoin/bitcoin/issues/19303#issuecomment-1514926359