opencanary: implement password redaction via gsub

[efd6]

Proposed commit message

opencanary: implement password redaction via gsub

The redact processor is not available for basic subscriptions, so
replace it with gsub to prevent CI failing when testing with that
subscription. This allows us to re-enable the testing of this
behaviour.

Checklist

• I have reviewed tips for building integrations and this pull request is aligned with them.
• I have verified that all data streams collect metrics or logs.
• I have added an entry to my package's changelog.yml file.
• I have verified that Kibana version constraints are current according to guidelines.
• I have verified that any added dashboard complies with Kibana's Dashboard good practices

Author's Checklist

• [ ]

How to test this PR locally

Related issues

• Ref beelzebub: implement password redaction via gsub #14035
• Ref opencanary: do not test redact-enabled pipeline #13551

Screenshots

[elastic-vault-github-plugin-prod]

🚀 Benchmarks report

To see the full report comment with /test benchmark fullreport

[elastic-sonarqube]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
75.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube

[elasticmachine]

💚 Build Succeeded

• Buildkite Build
• Commit: 416db5d

cc @efd6

[elasticmachine]

Pinging @elastic/security-service-integrations (Team:Security-Service Integrations)

[elastic-vault-github-plugin-prod]

Package opencanary - 0.5.0 containing this change is available at https://epr.elastic.co/package/opencanary/0.5.0/