Conversion to `SR` of a power series variable adds an unnecessary coefficient "1*"

[maxale]

Steps To Reproduce

No response

Expected Behavior

It is natural to expect that code:

R3.<t> = QQ[[]]
print( SR(t) )

would print just t.

Actual Behavior

Instead, it prints 1*t, that is, with the extra unnecessary coefficient 1.

Additional Information

The issue is split from #34695

Environment

- **OS**: Ubuntu 22.04.4
- **Sage Version**: 10.5.beta0

Checklist

• [X] I have searched the existing issues for a bug report that matches the one I want to file, without success.
• [X] I have read the documentation and troubleshoot guide

[DaveWitteMorris]

The output is correct, so this is not a bug. On the other hand, it would be better not to print the coefficient 1.