Add nil guard when audit fails when fixing vuln

[attiasas]

• All tests passed. If this feature is not already covered by the tests, I added new tests.
• This pull request is on the dev branch.
• I used gofmt for formatting the code before submitting the pull request.
• Update documentation about new features / new supported technologies

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Fix panic when Audit failed and configure to fail on any error

when FailUponAnyScannerError=true in the scan and audit fail:

2026-06-11T10:15:13.7070841Z 10:15:13 [Warn] An error occurred during Audit execution for 'main' branch. Fixes will be skipped for this branch

we get:

2026-06-11T10:15:13.7866231Z panic: runtime error: invalid memory address or nil pointer dereference
2026-06-11T10:15:13.7866968Z [signal 0xc0000005 code=0x0 addr=0x60 pc=0x7ff606316fca]
2026-06-11T10:15:13.7867209Z 
2026-06-11T10:15:13.7867916Z goroutine 1 [running]:
2026-06-11T10:15:13.7868821Z github.com/jfrog/jfrog-cli-security/utils/results.(*SecurityCommandResults).IncludesVulnerabilities(...)
2026-06-11T10:15:13.7869524Z         /Users/erant/go/pkg/mod/github.com/jfrog/jfrog-cli-security@v1.29.3/utils/results/results.go:523
2026-06-11T10:15:13.7870135Z github.com/jfrog/frogbot/v3/scanrepository.(*ScanRepositoryCmd).createVulnerabilitiesMap(0xda85bff8240, 0x0, 0x0)
2026-06-11T10:15:13.7870778Z         /Users/erant/Desktop/jfrog/frogbot/scanrepository/scanrepository.go:502 +0x4a
2026-06-11T10:15:13.7871395Z github.com/jfrog/frogbot/v3/scanrepository.(*ScanRepositoryCmd).scanAndFixBranch(0xda85bff8240, 0xda85c2a1508)
2026-06-11T10:15:13.7872062Z         /Users/erant/Desktop/jfrog/frogbot/scanrepository/scanrepository.go:165 +0x1aa
2026-06-11T10:15:13.7872739Z github.com/jfrog/frogbot/v3/scanrepository.(*ScanRepositoryCmd).prepareEnvAndScanBranch(0xda85bff8240, 0xda85c2a1508)
2026-06-11T10:15:13.7873333Z         /Users/erant/Desktop/jfrog/frogbot/scanrepository/scanrepository.go:112 +0x1e9