Update relayer inventory config (#76)

### What was the problem?

This PR resolves #LISK-1146

### How was it solved?

- [x] Updated relayer inventory config
- [x] Cleanup appspec.yml
- [x] Improve PR CI to check that docker images are built successfully

### How was it tested?

- Relayer setup: Local dev scripts
  - `sh scripts/lisk/docker/dev/composeStart.sh`
  - `sh scripts/lisk/docker/dev/composeStop.sh`
- Workflow changes: `act -C . -W ./.github/workflows/pr.yaml
--container-architecture linux/amd64 --pull --rm`

.github/workflows/pr.yaml

@@ -6,7 +6,7 @@ on:
 jobs:
   build-and-test:
     runs-on: ubuntu-latest
-    timeout-minutes: 30 # `yarn test` takes longer time
+    timeout-minutes: 30 # `yarn test` takes long time
     steps:
       - name: Checkout
         uses: actions/checkout@v4
@@ -36,3 +36,18 @@ jobs:
       - name: Test
         shell: bash
         run: yarn test
+
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+      - name: Build the Docker image
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: Dockerfile
+          push: false
+          platforms: linux/amd64

appspec.yml

@@ -6,7 +6,5 @@ files:
 hooks:
   ApplicationStop:
     - location: scripts/lisk/docker/composeStop.sh
-      timeout: 330
   ApplicationStart:
     - location: scripts/lisk/docker/composeStart.sh
-      timeout: 300

config/mainnet/relayerExternalInventory.json

@@ -18,23 +18,23 @@
       "1135": {
         "targetPct": 30,
         "thresholdPct": 10,
+        "targetOverageBuffer": 3,
         "unwrapWethThreshold": 0.025,
-        "unwrapWethTarget": 0.1,
-        "targetOverageBuffer": 1.5
+        "unwrapWethTarget": 0.1
       }
     },
     "LSK": {
       "1135": {
         "targetPct": 30,
-        "thresholdPct": 10,
-        "targetOverageBuffer": 2.5
+        "thresholdPct": 15,
+        "targetOverageBuffer": 3
       }
     },
     "USDT": {
       "1135": {
         "targetPct": 30,
-        "thresholdPct": 10,
-        "targetOverageBuffer": 1.5
+        "thresholdPct": 15,
+        "targetOverageBuffer": 3
       }
     }
   }