ci: add runs-on S3 cache for bun dependencies

Use runs-on/cache@v4 to cache ~/.bun/install/cache with S3 backend
for faster dependency installation across all CI jobs.

Author: amondnet

.github/workflows/ci.yml

@@ -20,6 +20,12 @@ jobs:
         with:
           bun-version: latest
 
+      - uses: runs-on/cache@v4
+        with:
+          path: ~/.bun/install/cache
+          key: bun-cache-${{ hashFiles('**/bun.lock') }}
+          restore-keys: bun-cache-
+
       - name: Install dependencies
         run: bun install
 
@@ -35,6 +41,12 @@ jobs:
         with:
           bun-version: latest
 
+      - uses: runs-on/cache@v4
+        with:
+          path: ~/.bun/install/cache
+          key: bun-cache-${{ hashFiles('**/bun.lock') }}
+          restore-keys: bun-cache-
+
       - name: Install dependencies
         run: bun install
 
@@ -50,6 +62,12 @@ jobs:
         with:
           bun-version: latest
 
+      - uses: runs-on/cache@v4
+        with:
+          path: ~/.bun/install/cache
+          key: bun-cache-${{ hashFiles('**/bun.lock') }}
+          restore-keys: bun-cache-
+
       - name: Install dependencies
         run: bun install
 

.github/workflows/release-please.yml

@@ -53,6 +53,12 @@ jobs:
           node-version: '22'
           registry-url: 'https://registry.npmjs.org'
 
+      - uses: runs-on/cache@v4
+        with:
+          path: ~/.bun/install/cache
+          key: bun-cache-${{ hashFiles('**/bun.lock') }}
+          restore-keys: bun-cache-
+
       - name: Install dependencies
         run: bun install