package.json,CI.yml: add devDependencies

This commit moved these dependencies to our `packages.json`
file. This allows us to manage all our dependencies in one
place and keep our project organized. Instead of adding each
package individually, we now simply execute `yarn` to install
all the packages specified in our `packages.json` file.

.github/workflows/CI.yml

@@ -94,10 +94,10 @@ jobs:
         run: |
           npm install conventional-changelog-conventionalcommits
           npm install commitlint@latest
-      - name: Install yarn
+      - name: Install yarn & packages
         run: |
           npm install --global yarn
-          yarn add --dev jest typescript ts-jest @types/jest
+          yarn
       - name: Print versions
         run: |
           git --version
@@ -130,10 +130,10 @@ jobs:
         run: |
           npm install conventional-changelog-conventionalcommits
           npm install commitlint@latest
-      - name: Install yarn
+      - name: Install yarn & packages
         run: |
           npm install --global yarn
-          yarn add --dev jest typescript ts-jest @types/jest ts-node
+          yarn
       - name: Run typescript compiler
         run: npx tsc
       - name: Print versions

package.json

@@ -1,5 +1,12 @@
 {
     "dependencies": {
-      "cosmiconfig": "8.0.0"
+        "cosmiconfig": "8.0.0"
+    },
+    "devDependencies": {
+        "@types/jest": "^29.5.11",
+        "jest": "^29.7.0",
+        "ts-jest": "^29.1.2",
+        "ts-node": "^10.9.2",
+        "typescript": "^5.3.3"
     }
 }