feat: add caching for pipelines (#384)

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## This PR
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- adds npm caching in all pipelines, with cache setup node takes 5s
against 12s of before

![image](https://user-images.githubusercontent.com/89971034/227175858-703a6145-dced-425b-9ca1-19c7851c5b7a.png)


### Related Issues
<!-- add here the GitHub issue that this PR resolves if applicable -->

Fixes #310

### Notes
<!-- any additional notes for this PR -->
since 14 is now too old, we decided that 16 was the best version to
avoid breaking changes

---------

Signed-off-by: realanna <[email protected]>

Author: RealAnna

.github/workflows/coverage.yml

@@ -16,6 +16,8 @@ jobs:
       - uses: actions/setup-node@v3
         with:
           registry-url: 'https://registry.npmjs.org'
+          node-version: 16
+          cache: 'npm'
 
       - name: Install
         run: npm ci

.github/workflows/pr-checks.yaml

@@ -22,6 +22,9 @@ jobs:
     steps:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v3
+        with:
+          node-version: 16
+          cache: 'npm'
 
       - name: Install
         run: npm ci

.github/workflows/release-please.yml

@@ -31,6 +31,7 @@ jobs:
         with:
           node-version: 16
           registry-url: "https://registry.npmjs.org"
+          cache: 'npm'
       - name: Build Packages
         run: |
           npm ci

package.json

@@ -29,7 +29,7 @@
   },
   "homepage": "https://github.com/open-feature/js-sdk#readme",
   "engines": {
-    "node": ">=14"
+    "node": ">=16"
   },
   "devDependencies": {
     "@openfeature/flagd-provider": "~0.7.0",

packages/server/package.json

@@ -44,6 +44,9 @@
     "url": "https://github.com/open-feature/js-sdk/issues"
   },
   "homepage": "https://github.com/open-feature/js-sdk#readme",
+  "engines": {
+    "node": ">=16"
+  },
   "devDependencies": {
     "@openfeature/shared": "0.0.2"
   }