ci: update chart version index for a single chart

[j-zimnowoda]

I noticed that some PRs created by Helm chart bot have more that one dependency version number updated in the Chart.yaml file. Example: https://github.com/linode/apl-core/pull/1863/files#diff-1c892db7344feb10640b6353e7452859ca22f33e57737e167a4cc55d23ba91f2

This PR fixes that issue.

Testing:
In local environment: at ci/.env:

CI_UPDATE_TYPE='minor'
CI_HELM_CHART_NAME_FILTER='[]'
CI_GH_CREATE_PR='false'
CI_GIT_BASELINE_BRANCH='APL-11-1'
CI_GIT_LOCAL_BRANCH_ONLY='true'

then run

src/update-helm-chart-deps.mjs

then

git checkout ci-update-sealed-secrets-to-2.17.0

gd HEAD~1

You should see only one version updated

 dependencies:
   - name: argo-cd
     version: 6.7.3
@@ -60,7 +44,7 @@ dependencies:
     version: 6.11.2
     repository: https://grafana.github.io/helm-charts
   - name: sealed-secrets
-    version: 2.14.1
+    version: 2.17.0
     repository: https://bitnami-labs.github.io/sealed-secrets/
   - name: tekton-pipeline
     version: 1.0.2

[CasLubbers]

One minor comment but it works on my machine! ✅