[cherry-pick][1.13]Check whether the VolumeSnapshot's source PVC is nil before using it

[blackpiglet]

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[codecov[bot]]

Codecov Report

Attention: Patch coverage is 40.00000% with 3 lines in your changes are missing coverage. Please review.

Project coverage is 62.04%. Comparing base (6499444) to head (40eed65).

Files	Patch %	Lines
internal/volume/volumes_information.go	0.00%	2 Missing and 1 partial :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## release-1.13 #7789 +/- ## ================================================ + Coverage 61.66% 62.04% +0.37% ================================================ Files 262 262 Lines 28450 22428 -6022 ================================================ - Hits 17545 13915 -3630 + Misses 9667 7274 -2393 - Partials 1238 1239 +1 ```

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