pgsql: Update modules/injection_points/.gitignore

Update modules/injection_points/.gitignore

Thinko in c35f419d6efb, where an isolation test has been added to the
module.

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/0ad8153c1f4c7129ff19e8a41d142001d35c8514

Modified Files
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src/test/modules/injection_points/.gitignore | 1 +
1 file changed, 1 insertion(+)