chore(deps): pin dependencies (#3421)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| docker.io/timberio/vector | pinDigest |  -> `5604fcb` |
|
[ghcr.io/nginxinc/nginx-unprivileged](https://togithub.com/nginxinc/docker-nginx-unprivileged)
| pinDigest | -> `5b49ce2` |

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Co-authored-by: repo-jeeves[bot] <106431701+repo-jeeves[bot]@users.noreply.github.com>

kubernetes/main/apps/monitoring/loki/app/helm-release.yaml

@@ -93,7 +93,7 @@ spec:
       image:
         registry: ghcr.io
         repository: nginxinc/nginx-unprivileged
-        tag: 1.25-alpine
+        tag: 1.25-alpine@sha256:5b49ce26ad8555b649a5a5ea8ccdfabc742a284ab58cb7b7d7a56f178c5dd351
       topologySpreadConstraints:
         - maxSkew: 2
           topologyKey: kubernetes.io/hostname

kubernetes/main/apps/monitoring/vector/agent/helm-release.yaml

@@ -40,7 +40,7 @@ spec:
           main:
             image:
               repository: docker.io/timberio/vector
-              tag: 0.37.1-alpine
+              tag: 0.37.1-alpine@sha256:5604fcb069b71942e8a63154f47aeedaf53daf6c20926a6d4575b76e298318d6
             args: ["--config", "/etc/vector/vector.yaml"]
             env:
               PROCFS_ROOT: /host/proc

kubernetes/main/apps/monitoring/vector/aggregator/helm-release.yaml

@@ -57,7 +57,7 @@ spec:
           main:
             image:
               repository: docker.io/timberio/vector
-              tag: 0.37.1-alpine
+              tag: 0.37.1-alpine@sha256:5604fcb069b71942e8a63154f47aeedaf53daf6c20926a6d4575b76e298318d6
             args: ["--config", "/etc/vector/vector.yaml"]
     service:
       main: