Replace Ubuntu 20.04 support with 24.04

Replace support for Ubuntu 20.04 with 24.04

.github/workflows/build-IGC.yml

@@ -99,7 +99,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ubuntu_version: [ '20.04', '22.04' ]
+        ubuntu_version: [ '22.04', '24.04' ]
         llvm_ver: [ 14 ]
         compiler: [ gcc, clang ]
         include:
@@ -186,7 +186,7 @@ jobs:
         run: mkdir Artifacts
       - name: copying artifact from docker to github host
         run: sudo docker cp buildigc:/workspace/igc/build/DEB-FILES ./Artifacts
-      - uses: actions/upload-artifact@v2
+      - uses: actions/upload-artifact@v3
         with:
           name: IGC_Ubuntu${{ matrix.ubuntu_version }}_llvm${{ matrix.llvm_ver }}_${{ matrix.compiler }}-${{ steps.igc-current-short-Hash.outputs.sha_short }}
           path: ./Artifacts/DEB-FILES/*.deb

README.md

@@ -39,8 +39,8 @@ https://opensource.org/licenses/MIT
 
 IGC is continuously built and tested on the following 64-bit Linux operating systems:
 
+* Ubuntu 24.04
 * Ubuntu 22.04
-* Ubuntu 20.04
 
 
 ## Documentation
@@ -68,5 +68,5 @@ If you have any feedback or questions, please open an issue through the native g
 
 ## How to contribute
 
-Create a pull request on github.com with your changes. Ensure that your modifications build without errors. 
+Create a pull request on github.com with your changes. Ensure that your modifications build without errors.
 A maintainer will get in touch with you if there are any inquiries or concerns.