feat: use testcontainers for integration tests

.github/actions/docker.override.conf

@@ -0,0 +1,5 @@
+# This is a systemd unit override file that enables the Docker Remote API on localhost.
+# To take effect, it should be placed at /etc/systemd/system/docker.service.d/override.conf.
+[Service]
+ExecStart=
+ExecStart=/usr/bin/dockerd -H fd:// -H tcp://127.0.0.1:2375

.github/workflows/on-push.yaml

@@ -12,7 +12,7 @@ env:
   NODE_VERSION: 22.1.0
   BUF_VERSION: 1.42.0
   PYTHON_VERSION: 3.13
-  NEXTEST_VERSION: 0.9.88
+  NEXTEST_VERSION: 0.9.93
   CARGO_INCREMENTAL: 0
   CARGO_PROFILE_DEV_STRIP: "debuginfo"
 
@@ -112,7 +112,7 @@ jobs:
       - name: Run Unit Tests (Node)
         run: pnpm --recursive test
       - name: Run Unit Tests (Rust)
-        run: cargo-nextest nextest --color always run --no-fail-fast --archive-file nextest-archive.tar.zst
+        run: cargo-nextest nextest --config-file nextest.toml --color always run --no-fail-fast --archive-file nextest-archive.tar.zst
 
   # Runs the Rust integration tests for the project. It depends on the
   # `build-tests` job to build the nextest test archives and upload them as
@@ -174,7 +174,7 @@ jobs:
           name: nextest-archives
           path: .
       - name: Run Integration Tests (Rust)
-        run: cargo-nextest nextest --color always run --no-fail-fast --test-threads 1 --partition hash:${{ matrix.partition }}/2 --archive-file nextest-archive-serial.tar.zst
+        run: cargo-nextest nextest --config-file nextest.toml --color always run --no-fail-fast --partition hash:${{ matrix.partition }}/2 --archive-file nextest-archive-serial.tar.zst
 
   # Runs checks on the generated code in the project for contracts, the
   # blocklist client and the emily clients. This job is used to ensure that the