[AC-2941] ci: add pr-size-diff workflow (#294)

## Changes
Add `pr-size-diff` workflow

ticket: [AC-2941]

[AC-2941]:
https://sendbird.atlassian.net/browse/AC-2941?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

.github/workflows/pr-comment-bot.yml

@@ -6,7 +6,7 @@ jobs:
   pr-comment:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       # see list of commands: https://github.com/sendbird/release-automation-action#commands
       - uses: sendbird/release-automation-action@latest
         with:

.github/workflows/pr-size-diff.yml

@@ -0,0 +1,25 @@
+name: PR size diff
+
+on: [pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          submodules: 'recursive'
+          fetch-depth: 0
+      - name: Enable corepack
+        run: corepack enable
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 18.x
+          cache: 'yarn'
+      - uses: preactjs/compressed-size-action@v2
+        with:
+          pattern: "./dist/**/*.{js,css}"
+          exclude: "{**/*.d.ts,**/node_modules/**}"
+          strip-hash: "\\w+-([a-zA-Z0-9_-]{8})\\.js$"

src/css/index.css

@@ -112,4 +112,4 @@ input:focus {
 .sendbird-suggested-replies {
   margin: 0 !important;
   padding: 8px 0 16px;
-}
+}