fix: remove second call to finalize as the task handles it

[spiffcs]

Summary

Closes #2509

This PR removes the double call to relationships.Finalize.

To validate the fix run the following using the latest release of syft:

syft cgr.dev/chainguard/coredns@sha256:238f7d4cff40ffa7262ae5508481722fe3213e4aae1e61a1425f07f4ae2e4d71 -qo json | jq .artifactRelationships > test.json

Then using this gist you can evaluate the output relationships from above and find the dupes:
https://gist.github.com/spiffcs/72b641f04ac79d160ce079bcd3816382

Duplicate relationship: Parent=007a689559786815, Child=0fdca611631006c5 Type=ownership-by-file-overlap
Duplicate relationship: Parent=007a689559786815, Child=fe672ea9910662d8 Type=evident-by
Duplicate relationship: Parent=014167b5dbcc5b66, Child=2d14b57d501102cf Type=evident-by
Duplicate relationship: Parent=02619b1e06d34738, Child=2d14b57d501102cf Type=evident-by
Duplicate relationship: Parent=03dd022f997618f7, Child=2d14b57d501102cf Type=evident-by
Duplicate relationship: Parent=04e552bdca0b46d0, Child=2d14b57d501102cf Type=evident-by
Duplicate relationship: Parent=0c54b26b7af957a5, Child=2d14b57d501102cf Type=evident-by
Duplicate relationship: Parent=0dbbe7127f2505bf, Child=2d14b57d501102cf Type=evident-by
Duplicate relationship: Parent=0e1e0f87146ef9a2, Child=2d14b57d501102cf Type=evident-by
Duplicate relationship: Parent=0f024cac5c4c3f57, Child=2d14b57d501102cf Type=evident-by
Duplicate relationship: Parent=0fdca611631006c5, Child=d2414b428d31083d Type=evident-by
Duplicate relationship: Parent=19408370ed916ebd, Child=2d14b57d501102cf Type=evident-by
Duplicate relationship: Parent=1e3d85055de3fdbe, Child=2d14b57d501102cf Type=evident-by
...

Run the same command as above using the tip of this branch:

go run cmd/syft/main.go cgr.dev/chainguard/coredns@sha256:238f7d4cff40ffa7262ae5508481722fe3213e4aae1e61a1425f07f4ae2e4d71 -qo json | jq .artifactRelationships > test.json

And then rerun the gist again on the output:
https://gist.github.com/spiffcs/72b641f04ac79d160ce079bcd3816382

There should no longer be any duplicates shown in the output

...

An integration test has also been added to project against this regression going forward where duplicate edges are not tolerated for the given image-pkg-coverage. The test was checked for failure against the change and shown to fail if the second Finalize call was not removed