Preserve async module order across repeat-until-failure runs

[cuishuang]

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--repeat-until-failure restores async modules after each successful run.

The runner stores modules in execution order, but ExUnit.Server.restore_modules/2 reconstructed the internal queue and group state using the opposite ordering.

As a result, subsequent runs could reverse:

• the order of ungrouped async modules;
• the order of async groups;
• the order of modules within each async group.

This change converts the runner representation back to the server's internal representation before restoring it, preserving FIFO order across repeated runs.

• make test_ex_unit