Fix composable loop reinit bug

[MaxSchambach]

Description

Fixes a tiny but significant bug in loop method of Composable class.
Running an infinite loop previously resulted in yielding only the very first item of the IterableSource due to a reinitialization of the iterator caused by a wrong indentation level.

The fix is straightforward by correcting the indentation level of the iterator reinitialization.

A test is added to testcase the infinite-loop setting which was previously untested.

See the test or this simple snippet to showcase the bug:

from squirrel.iterstream.source import IterableSource

source = IterableSource(range(3)).loop()

for i, x in enumerate(source):
    print(x)
    if i == 9:
        break
# previously yielded [0, 0, ..., 0], should yield [0, 1, 2, ..., 1, 2]

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Refactoring including code style reformatting
• Other (please describe):

Checklist:

• I have read the contributing guideline doc (external contributors only)
• Lint and unit tests pass locally with my changes
• I have kept the PR small so that it can be easily reviewed
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• All dependency changes have been reflected in the pip requirement files.

[AlirezaSohofi]

Nice catch, thanks a lot for the fix 👍

[AlirezaSohofi]

@MaxSchambach can you please increment the version?

[MaxSchambach]

Thanks! Version is bumped.

[AlirezaSohofi]

👍