test: remove unused file

This removes a source file that got re-added via a rebase.
It seems somewhere around change set
178dff2
`entry_point.c` was removed, and rebase
0b6e16f
added it back. The review of #48740
overlooked this and the file got re-committed.

PR-URL: #50528
Reviewed-By: Luigi Pinca <[email protected]>
Reviewed-By: Chengzhong Wu <[email protected]>
Reviewed-By: Vladimir Morozov <[email protected]>
Reviewed-By: Tobias Nießen <[email protected]>

Author: jsumners