CMake fix for sporadic flush2 failures (#692)

* Committing clang-format changes

* Runs the flush1/flush2 tests in their own directory

Avoids file deletions by other tests.

* Revert "Runs the flush1/flush2 tests in their own directory"

This reverts commit 746c048.

Also pulls the flush files from the clean list, which is a simpler fix.

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

test/CMakeTests.cmake

@@ -318,14 +318,6 @@ set (test_CLEANFILES
     tvlstr.h5
     tvlstr2.h5
     twriteorder.dat
-    flush.h5
-    flush-swmr.h5
-    noflush.h5
-    noflush-swmr.h5
-    flush_extend.h5
-    flush_extend-swmr.h5
-    noflush_extend.h5
-    noflush_extend-swmr.h5
     enum1.h5
     titerate.h5
     ttsafe.h5