Apply pretty_assertions::assert_eq! to core/ ast_builder unit tests

[panarch]

No description provided.

[coveralls]

Pull Request Test Coverage Report for Build 5774831682

• 3 of 3 (100.0%) changed or added relevant lines in 1 file are covered.
• 7 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.06%) to 98.521%

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Files with Coverage Reduction	New Missed Lines	%
core/src/ast_builder/select/join/join_constraint.rs	1	99.42%
core/src/ast_builder/select/join/hash_join.rs	2	99.21%
core/src/ast_builder/select/join/root.rs	4	99.37%

Totals
Change from base Build 5774101897:	-0.06%
Covered Lines:	45416
Relevant Lines:	46098

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💛 - Coveralls