Handle self-loops in all_simple_paths (backport #1619)

[mergify]

Closes #1617

This was a discrepancy introduced in #1520. For the record, NetworkX returns ["a"] for a self-loop which is slightly different than ["a", "a"] but I think the old behaviour is fine.

---

This is an automatic backport of pull request #1619 done by Mergify.

[coveralls]

Coverage Report for CI Build 29058793256

Coverage decreased (-0.02%) to 94.696%

Details

• Coverage decreased (-0.02%) from the base build.
• Patch coverage: 4 uncovered changes across 1 file (18 of 22 lines covered, 81.82%).
• No coverage regressions found.

Uncovered Changes

File	Changed	Covered	%
src/connectivity/mod.rs	22	18	81.82%

Coverage Regressions

No coverage regressions found.

---

Coverage Stats

Relevant Lines:	20307
Covered Lines:	19230
Line Coverage:	94.7%
Coverage Strength:	920401.97 hits per line

---

💛 - Coveralls

[mergify]

Tick the box to add this pull request to the merge queue (same as @mergifyio queue).

• Queue this pull request