[dashboard] Fix bitnami dependencies (#1431)

Signed-off-by: Andrei Kvapil <kvapss@gmail.com>

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## What this PR does


### Release note

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```release-note
[]
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## Summary by CodeRabbit

- Chores
- Updated container base images for the dashboard and APIs to maintained
legacy variants to improve build stability and align with security
patching.
- No user-facing changes: functionality, performance, and UI remain
unchanged.
- Runtime versions are consistent with previous releases; deployment
artifacts are equivalent.
- Existing workflows and configurations continue to work as before; no
action required from users.

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packages/system/dashboard/images/dashboard/Dockerfile

@@ -1,4 +1,4 @@
-FROM bitnami/node:20.15.1 AS build
+FROM bitnamilegacy/node:20.15.1 AS build
 WORKDIR /app
 
 ARG COMMIT_REF=4926bc68fabb0914afab574006643c85a597b371
@@ -26,5 +26,5 @@ RUN sed -i \
     -e 's/#1b2b32/#2a2d2f/g' \
     $(grep -rl "#2d4048\|#25333d\|#fcfdfd\|#f1f6f8\|#e3eaed\|#cbd4d8\|#aeb8bc\|#859399\|#6a7a81\|#4f6169\|#3a4d55\|#2d4048\|#21333b\|#1b2b32")
 
-FROM bitnami/nginx:1.25.2
+FROM bitnamilegacy/nginx:1.25.2
 COPY --from=build /app/build /app

packages/system/dashboard/images/kubeapps-apis/Dockerfile

@@ -9,7 +9,7 @@ RUN apk add --no-cache patch
 WORKDIR /source
 RUN wget -O- https://github.com/cozystack/kubeapps/archive/${COMMIT_REF}.tar.gz | tar xzf - --strip-components=1
 
-FROM bitnami/golang:1.23.4 AS builder
+FROM bitnamilegacy/golang:1.23.4 AS builder
 WORKDIR /go/src/github.com/vmware-tanzu/kubeapps
 COPY --from=source /source/go.mod /source/go.sum ./
 ARG TARGETOS