Update contracts-build.yml

* feat: add a release step to nym contracts GH action

* feat: add shrinking the size of wasm

.github/workflows/contracts-build.yml

@@ -1,16 +1,21 @@
 name: Build release of Nym smart contracts
 on:
   workflow_dispatch:
-
+  release:
-defaults:
+    types: [created]
-  run:
-    working-directory: contracts
 
 jobs:
   build:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
+      
+      - name: Check the release tag starts with `nym-contracts-`
+        if: startsWith(github.ref, 'refs/tags/nym-contracts-') == false && github.event_name != 'workflow_dispatch'
+        uses: actions/github-script@v3
+        with:
+          script: |
+            core.setFailed('Release tag did not start with nym-contracts-...')      
 
       - name: Install Rust stable
         uses: actions-rs/toolchain@v1
@@ -21,7 +26,7 @@ jobs:
           components: rustfmt, clippy
 
       - name: Build release contracts
-        run: RUSTFLAGS='-C link-arg=-s' cargo build --release --target wasm32-unknown-unknown
+        run: make wasm
 
       - name: Upload Mixnet Contract Artifact
         uses: actions/upload-artifact@v3
@@ -36,3 +41,11 @@ jobs:
           name: vesting_contract.wasm
           path: contracts/target/wasm32-unknown-unknown/release/vesting_contract.wasm
           retention-days: 5
+
+      - name: Upload to release based on tag name
+        uses: softprops/action-gh-release@v1
+        if: github.event_name == 'release'
+        with:
+          files: |
+            contracts/target/wasm32-unknown-unknown/release/vesting_contract.wasm
+            contracts/target/wasm32-unknown-unknown/release/mixnet_contract.wasm