Use nix docker tooling to build images (#91)

This PR includes:
- Build all the docker images both for production and testing using nix
dockerTools.
- Update the docker docs
- Update the justfile commands adding a new nix module to improve the
organization
- Remove all the dockerfiles

Author: arilotter

.github/workflows/push-docker.yml

@@ -0,0 +1,37 @@
+name: Push Client Image
+on:
+  check_suite:
+    types: [completed]
+
+jobs:
+  push-docker-image:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Set up Nix
+        uses: cachix/install-nix-action@v27
+        with:
+          extra_nix_config: |
+            accept-flake-config = true
+            substituters = https://cache.garnix.io https://cache.nixos.org/
+            trusted-public-keys = cache.garnix.io:CTFPyKSLcx5RMJKfLo5EEPUObbA78b0YQ2DTCJXqr9g= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
+
+      - name: Download image from Garnix cache
+        run: |
+          nix build .#docker-psyche-solana-client --no-link --print-out-paths > image-path.txt
+
+      - uses: DeterminateSystems/nix-installer-action@main
+      - uses: DeterminateSystems/magic-nix-cache-action@main
+
+      - name: Login to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ vars.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKER_DEPLOY_KEY }}
+
+      - run: scripts/push-client-image.sh
+        env:
+          DOCKER_REPOSITORY: ${{ vars.DOCKERHUB_REPO }}