Bump nginx from 1.21-alpine to 1.25-alpine (#74)

Bumps nginx from 1.21-alpine to 1.25-alpine.

---
updated-dependencies:
- dependency-name: nginx
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Dockerfile

@@ -151,7 +151,7 @@ WORKDIR /
 COPY --from=go_builder /build/mir-travel-time-calculator /mir-travel-time-calculator
 ENTRYPOINT [ "./mir-travel-time-calculator" ]
 
-FROM nginx:1.21-alpine as monitoring-ui
+FROM nginx:1.25-alpine as monitoring-ui
 WORKDIR /
 # Install SSL ca certificates
 RUN apk add --no-cache ca-certificates