perf: serial no creation (backport #50436)

[mergify]

Before Change

The system used to run a query to get the current value for each quantity. So, if the quantity was 200, the system would run 200 SQL queries.

After Change

Now, the system will run only two queries. The first query retrieves the current value of the prefix, and the second query updates the current value of the prefix in the tabSeries table after creation of all serial nos.

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This is an automatic backport of pull request #50436 done by Mergify.

[mergify]

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	both modified:   erpnext/stock/serial_batch_bundle.py

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