This PR enhances `isolation_multiuser_locking.spec` test compatibility
across multiple PostgreSQL versions by handling differences in error
messages and behavior. Key updates include:
- **Error Message Handling:** Adjustments to manage version-specific
error messages, ensuring consistent test results.
- Modified to address variations in locking behavior across PostgreSQL
versions, ensuring test stability in multiuser scenarios.
- **REINDEX Behavior Adjustment**: This PR accounts for a behavioral
change introduced in PostgreSQL by commit ecb0fd337, which alters how
REINDEX interacts with system catalogs.
https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=ecb0fd337
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Co-authored-by: Mehmet YILMAZ <mehmet.yilmaz@microsoft.com>