CHG | Update actions/cache version to 4.2.3 in main.yml; remove .github/ from .gitignore

Author: Paopun20

.github/workflows/main.yml

@@ -35,7 +35,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: confirm
     steps:
-      - uses: actions/cache@v4
+      - uses: actions/cache@v4.2.3
         with:
           path: |
             ~/.haxelib
@@ -157,7 +157,7 @@ jobs:
         with:
           cmake-version: '3.26.x'
       - name: Cache Dependencies
-        uses: actions/cache@v4
+        uses: actions/cache@v4.2.3
         with:
           path: |
             /usr/lib/i386-linux-gnu

.gitignore

@@ -9,7 +9,6 @@ art/buildScripts/test_x64-debug-officialrelease.bat
 export/*
 .vscode/*
 .haxelib/
-.github/
 *.code-workspace
 vs_Community.exe
 # Local history which shouldn't be shared.