Remove source build workflow and README entries

Author: fmauch

.github/workflows/humble-source-build.yml

@@ -40,10 +40,6 @@ Check also [presentations and videos](ur_robot_driver/doc/resources/README.md) a
       <a href="https://github.com/UniversalRobots/Universal_Robots_ROS2_Driver/actions/workflows/foxy-semi-binary-build.yml?query=event%3Aschedule++">
          <img src="https://github.com/UniversalRobots/Universal_Robots_ROS2_Driver/actions/workflows/foxy-semi-binary-build.yml/badge.svg?event=schedule"
               alt="Foxy Semi-Binary Build"/>
-      </a> <br />
-      <a href="https://github.com/UniversalRobots/Universal_Robots_ROS2_Driver/actions/workflows/foxy-source-build.yml?query=branch%3Afoxy+">
-         <img src="https://github.com/UniversalRobots/Universal_Robots_ROS2_Driver/actions/workflows/foxy-source-build.yml/badge.svg?branch=foxy"
-              alt="Foxy Source Build"/>
       </a>
     </td>
     <td>
@@ -54,10 +50,6 @@ Check also [presentations and videos](ur_robot_driver/doc/resources/README.md) a
       <a href="https://github.com/UniversalRobots/Universal_Robots_ROS2_Driver/actions/workflows/galactic-semi-binary-build.yml?query=event%3Aschedule++">
          <img src="https://github.com/UniversalRobots/Universal_Robots_ROS2_Driver/actions/workflows/galactic-semi-binary-build.yml/badge.svg?event=schedule"
               alt="Galactic Semi-Binary Build"/>
-      </a> <br />
-      <a href="https://github.com/UniversalRobots/Universal_Robots_ROS2_Driver/actions/workflows/galactic-source-build.yml?query=branch%3Agalactic+">
-         <img src="https://github.com/UniversalRobots/Universal_Robots_ROS2_Driver/actions/workflows/galactic-source-build.yml/badge.svg?branch=galactic"
-              alt="Galactic Source Build"/>
       </a>
     </td>
     <td>
@@ -68,10 +60,6 @@ Check also [presentations and videos](ur_robot_driver/doc/resources/README.md) a
       <a href="https://github.com/UniversalRobots/Universal_Robots_ROS2_Driver/actions/workflows/humble-semi-binary-build.yml?query=event%3Aschedule++">
          <img src="https://github.com/UniversalRobots/Universal_Robots_ROS2_Driver/actions/workflows/humble-semi-binary-build.yml/badge.svg?event=schedule"
               alt="Humble Semi-Binary Build"/>
-      </a> <br />
-      <a href="https://github.com/UniversalRobots/Universal_Robots_ROS2_Driver/actions/workflows/humble-source-build.yml?query=branch%3Ahumble">
-         <img src="https://github.com/UniversalRobots/Universal_Robots_ROS2_Driver/actions/workflows/humble-source-build.yml/badge.svg?branch=humble"
-              alt="Humble Source Build"/>
       </a>
     </td>
     <td>
@@ -82,17 +70,13 @@ Check also [presentations and videos](ur_robot_driver/doc/resources/README.md) a
       <a href="https://github.com/UniversalRobots/Universal_Robots_ROS2_Driver/actions/workflows/rolling-semi-binary-build.yml?query=branch%3Amain+">
          <img src="https://github.com/UniversalRobots/Universal_Robots_ROS2_Driver/actions/workflows/rolling-semi-binary-build.yml/badge.svg?branch=main"
               alt="Rolling Semi-Binary Build"/>
-      </a> <br />
-      <a href="https://github.com/UniversalRobots/Universal_Robots_ROS2_Driver/actions/workflows/rolling-source-build.yml?query=branch%3Amain+">
-         <img src="https://github.com/UniversalRobots/Universal_Robots_ROS2_Driver/actions/workflows/rolling-source-build.yml/badge.svg?branch=main"
-              alt="Rolling Source Build"/>
       </a>
     </td>
   </tr>
 </table>
 
 
-**NOTE**: There are three build stages checking current and future compatibility of the driver.
+**NOTE**: There are two build stages checking current and future compatibility of the driver.
 
 1. Binary builds - against released packages (main and testing) in ROS distributions. Shows that direct local build is possible.
 
@@ -103,8 +87,6 @@ Check also [presentations and videos](ur_robot_driver/doc/resources/README.md) a
 
    Uses repos file: `src/Universal_Robots_ROS2_Driver/Universal_Robots_ROS2_Driver.repos`
 
-1. Source build - also core ROS packages are build from source. It shows potential issues in the mid future.
-
 Each of these stages also performs integration tests using ursim. In order to execute these tests locally, they have to be enabled:
   ```
   colcon build --packages-select ur_robot_driver --cmake-args -DUR_ROBOT_DRIVER_BUILD_INTEGRATION_TESTS=On