fix: removing underscore from VulnerabilityReport names

[matheusfm]

Description

This PR fixes a bug in worker container when creating VulnerabilityReports for images named with underscore.

2024-06-05T20:06:48Z	ERROR	worker	failed to run worker	{"error": "failed to create VulnerabilityReport \"kind-kind-mfmoraesnginxx86_64latest-q758l\": VulnerabilityReport.zora.undistro.io \"kind-kind-mfmoraesnginxx86_64latest-q758l\" is invalid: metadata.name: Invalid value: \"kind-kind-mfmoraesnginxx86_64latest-q758l\": a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')"}
main.main
	/workspace/cmd/worker/main.go:42
runtime.main
	/usr/local/go/src/runtime/proc.go:267

Linked Issues

UD-1516

How has this been tested?

1. Create a cluster and run a pod with an image named with underscore:

kind create cluster
kubectl run nginx --image=mfmoraes/nginxx86_64:latest --image-pull-policy=IfNotPresent

2. Install Zora and wait for the vulnerability scan.

3. Check if a vulnerability report for mfmoraes/nginxx86_64:latest image is created.

kubectl get vulns -n zora-system | grep nginx

4. We expect to see:

kind-kind-mfmoraesnginxx8664latest-6m7rk                               kind-kind   mfmoraes/nginxx86_64:latest                                   102     2          15     86s

Checklist

• I have labeled this PR with the relevant Type labels
• I have documented my code (if applicable)
• My changes are covered by tests