Upgrade tests are too much version specific

It seems like we run bunch of the upgrade tests with only a specific from/to versions such as:
```SQL
-- run this test only when old citus version is 9.0
\set upgrade_test_old_citus_version `echo "$upgrade_test_old_citus_version"`
SELECT substring(:'upgrade_test_old_citus_version', 'v(\d+)\.\d+\.\d+')::int = 9 AND
substring(:'upgrade_test_old_citus_version', 'v\d+\.(\d+)\.\d+')::int = 0
AS upgrade_test_old_citus_version_e_9_0;
upgrade_test_old_citus_version_e_9_0
---------------------------------------------------------------------
t
(1 row)

\gset
\if :upgrade_test_old_citus_version_e_9_0
\else
\q
\endif
```

When I try to remove this, upgrade_columnar_metapage_after.out - /Users/onderkalaci/Documents/citus_code/citus/src/test/regress/expected

seems to fail, where `reserved_row_number ` changes.

We should (a) make upgrade tests depend less on specific versions (b) understand why `reserved_row_number` changes

Might be related to https://github.com/citusdata/citus/pull/4920/files#