Exclude non-rc pre-releases from qpy backwards compat tests (#11572) (#…

…11574)

The QPY backwards compatibility tests are setup to verify that we can
load qpy files generated with historical releases using the current
version of Qiskit under development. This ensures we're meeting our
backwards compatibility guarantees with QPY. However, the tests were
over eagerly running on pre-releases that don't have any stability
guarantees, mainly alpha and beta releases indicated by "a" and "b"
suffixes respectively in the version number. This commit excludes
these pre-release versions from the tests as it's not valid to
run with these. Release candidate pre-releases should still be run
because they have stable APIs and they're not skipped by this PR.

(cherry picked from commit abb803f)

Co-authored-by: Matthew Treinish <[email protected]>

test/qpy_compat/process_version.sh

@@ -29,6 +29,11 @@ if [[ ${parts[0]} -eq 0 && ${parts[1]} -lt 18 ]] ; then
     exit 0
 fi
 
+# Exclude any non-rc pre-releases as they don't have stable API guarantees
+if [[ $version == *"b"* || $version == *"a"* ]] ; then
+    exit 0
+fi
+
 # If the source version is newer than the version under test exit fast because
 # there is no QPY compatibility for loading a qpy file generated from a newer
 # release with an older release of Qiskit.