build: update Dockerfile, endeveit/docker-jq is not available anymore

Dockerfile

@@ -1,16 +1,10 @@
-# https://stackoverflow.com/a/58487433
-# To prevent cache invalidation from changes in fields other than dependencies
-
-FROM --platform=$BUILDPLATFORM endeveit/docker-jq AS deps
-COPY package.json /tmp
-RUN jq '{ dependencies, devDependencies }' < /tmp/package.json > /tmp/deps.json
-
 FROM --platform=$BUILDPLATFORM node:current-alpine AS build
 WORKDIR /activity-roles/
-RUN apk add python3 make g++
+RUN apk add python3 make g++ jq
 RUN npm i -g pnpm
 COPY tsconfig.json pnpm-lock.yaml .
-COPY --from=deps /tmp/deps.json ./package.json
+COPY package.json /tmp
+RUN jq '{ dependencies, devDependencies }' < /tmp/package.json > ./package.json
 RUN pnpm i
 COPY src src
 RUN ./node_modules/typescript/bin/tsc --outDir out/
@@ -22,7 +16,7 @@ RUN npm i -g pnpm
 COPY img/discord-header.png img/discord-header.png
 COPY locales locales
 COPY pnpm-lock.yaml .
-COPY --from=deps /tmp/deps.json ./package.json
+COPY --from=build /activity-roles/package.json ./package.json
 RUN pnpm i -P
 COPY --from=build /activity-roles/out src