pg_dump: fix installcheck failure tests in src/bin/pg_dump

[gongxun0928]

1. the pattern of DYNAMIC TABLE with SCHEDULE is wrong, fix it
2. pg_dump with multijob mode will create multiple connections in same ArchiveHandle
3. sql syntax error in dumpAgg.

/usr/bin/mkdir -p '/code/cloudberry/src/bin/pg_dump'/tmp_check cd . && TESTDIR='/code/cloudberry/src/bin/pg_dump' PATH="/home/gpadmin/install/gpdb/bin:/code/cloudberry/src/bin/pg_dump:$PATH" PGPORT='65432' top_builddir='/code/cloudberry/src/bin/pg_dump/../../..' PG_REGRESS='/code/cloudberry/src/bin/pg_dump/../../../src/test/regress/pg_regress' /usr/bin/prove -I ../../../src/test/perl/ -I . t/*.pl t/001_basic.pl ................ ok t/002_pg_dump.pl .............. ok t/003_pg_dump_with_server.pl .. ok t/010_dump_connstr.pl ......... ok All tests successful. Files=4, Tests=7171, 56 wallclock secs ( 0.40 usr 0.05 sys + 9.43 cusr 3.94 csys = 13.82 CPU) Result: PASS

Fixes #ISSUE_Number

What does this PR do?

Type of Change

• [ ] Bug fix (non-breaking change)
• [ ] New feature (non-breaking change)
• [ ] Breaking change (fix or feature with breaking changes)
• [ ] Documentation update

Breaking Changes

Test Plan

• [ ] Unit tests added/updated
• [ ] Integration tests added/updated
• [ ] Passed make installcheck
• [ ] Passed make -C src/test installcheck-cbdb-parallel

Impact

Performance:

User-facing changes:

Dependencies:

Checklist

• [ ] Followed contribution guide
• [ ] Added/updated documentation
• [ ] Reviewed code for security implications
• [ ] Requested review from cloudberry committers

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