[CI] Update dependency databus23/helm-diff to v3.15.12

[renovate]

This PR contains the following updates:

Package	Update	Change
databus23/helm-diff	patch	3.15.11 → 3.15.12

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Release Notes

databus23/helm-diff (databus23/helm-diff)

v3.15.12

Compare Source

What's Changed

• feat: omit 'app.kubernetes.io/managed-by' label on three-way-diff by @​jkroepke in #​1044
• Pass --revision to helm diff upgrade by @​sepich in #​1046
• Bump Helm support matrix to v3.21.4 and v4.2.4 by @​yxxhero with @​Copilot in #​1049
• build(deps): bump oras.land/oras-go/v2 from 2.6.1 to 2.6.2 by @​dependabot[bot] in #​1050
• build(deps): bump k8s.io/apimachinery from 0.36.3 to 0.36.4 by @​dependabot[bot] in #​1055
• build(deps): bump k8s.io/api from 0.36.3 to 0.36.4 by @​dependabot[bot] in #​1054
• build(deps): bump k8s.io/client-go from 0.36.3 to 0.36.4 by @​dependabot[bot] in #​1053
• build(deps): bump k8s.io/cli-runtime from 0.36.3 to 0.36.4 by @​dependabot[bot] in #​1051
• build(deps): bump k8s.io/apiextensions-apiserver from 0.36.3 to 0.36.4 by @​dependabot[bot] in #​1052
• Add external diff tool support by @​eagafonov in #​1048
• feat: add --storage-namespace flag and HELM_DIFF_STORAGE_NAMESPACE env var by @​asouchang in #​1056
• chore: bump plugin version to 3.15.12 by @​yxxhero in #​1057

New Contributors

• @​sepich made their first contribution in #​1046
• @​eagafonov made their first contribution in #​1048
• @​asouchang made their first contribution in #​1056

Full Changelog: databus23/helm-diff@v3.15.11...v3.15.12

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