pin dependancies and replace yarn with pnpm

.github/COEDOWNERS

@@ -0,0 +1,3 @@
+# Require reviews from Solidity reviewers for .sol files
+
+.sol @OriginProtocol/core

.github/workflows/abi.yml

@@ -16,18 +16,28 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - name: Install pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: 10
+          run_install: false
+
       - name: Use Node.js
         uses: actions/setup-node@v4
         with:
           node-version: "20.x"
-          cache: "yarn"
-          cache-dependency-path: contracts/yarn.lock
+          cache: "pnpm"
+          cache-dependency-path: contracts/pnpm-lock.yaml
+
+      - name: Configure Git to use HTTPS for GitHub
+        run: git config --global url."https://github.com/".insteadOf "[email protected]:"
 
-      - run: yarn install --frozen-lockfile
+      - name: Install deps
         working-directory: ./contracts
+        run: pnpm install --frozen-lockfile
 
       - name: "Generate ABI files"
-        run: (yarn run abi:generate) && (yarn run abi:dist)
+        run: (pnpm run abi:generate) && (pnpm run abi:dist)
         env:
           CONTRACT_SIZE: true
         working-directory: ./contracts