Merge main branch and resolve conflicts while maintaining EOL platform removal

Author: Copilot

.github/workflows/build-ubuntu-2004.yml .github/workflows/build-ubuntu-2204.yml.github/workflows/build-ubuntu-2004.yml renamed to .github/workflows/build-ubuntu-2204.yml

@@ -1,4 +1,4 @@
-name: C/C++ CI on Ubuntu 20.04
+name: C/C++ CI on Ubuntu 22.04
 
 on:
   push:
@@ -28,11 +28,11 @@ jobs:
     strategy:
       matrix:
         config: [release, debug]
-        os: [ubuntu-20.04]
+        os: [ubuntu-22.04]
 
     steps:
     - name: Checkout
       uses: actions/checkout@v1
       continue-on-error: true
     - name: Test ${{ matrix.os }} ${{ matrix.config }}
-      run: ./build-tests.sh ${{ matrix.config }}
+      run: ./build-tests.sh ${{ matrix.config }}

README.md

@@ -66,7 +66,7 @@ Other resources to learn how to setup the build system:
   | Operating System              | Compiler                         |
   | ----------------------------- | -------------------------------- |
   | macOS 10.15+                  | Clang Xcode 12.0+                |
-  | Ubuntu 20.04 LTS              | GCC 9.x.x                        |  
+  | Ubuntu 20.04 LTS              | GCC 9.x.x                        |
   | Ubuntu 22.04 LTS              | GCC 11.x.x                       |
   | Windows 10                    | Android Studio/Gradle            |
   | Windows Server 2016           | Visual Studio 2017 (vc141)       |
@@ -83,7 +83,7 @@ Other resources to learn how to setup the build system:
   | macOS 10.15+                   | :white_check_mark: |                    |
   | macOS (latest)                 | :white_check_mark: | :white_check_mark: |
   | Ubuntu 20.04.x LTS             | :white_check_mark: | :white_check_mark: |
-  | Ubuntu 22.04.x LTS             | :white_check_mark: |                    |
+  | Ubuntu 22.04.x LTS             | :white_check_mark: | :white_check_mark: |
   | Ubuntu (latest)                | :white_check_mark: | :white_check_mark: |
   | Windows 10.x                   | :white_check_mark: |                    |
   | Windows 11                     | :white_check_mark: |                    |

docker/ubuntu22.04/Dockerfile

@@ -0,0 +1,22 @@
+FROM ubuntu:22.04
+
+ENV DEBIAN_FRONTEND noninteractive
+
+# Package installation
+RUN apt-get update
+
+## Common packages for linux build environment
+RUN apt install -y clang python3 pkg-config git curl nghttp2 bzip2 unzip make wget cmake sudo
+
+RUN adduser --disabled-password --gecos '' docker
+RUN adduser docker sudo
+RUN echo '%sudo ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers
+## RUN useradd -m docker && echo "docker:docker" | chpasswd && adduser docker sudo
+## USER docker
+
+# this is where I was running into problems with the other approaches
+RUN sudo apt-get update
+
+CMD /bin/bash
+
+# ENTRYPOINT bash