Update 3.3.x to be a supported branch (#5941)

* Preparing everything for branchout of 3.3.x

Signed-off-by: Emilio Cuesta <emiliocuesta@eprosima.com>

* Updating README links to workflows

Signed-off-by: Emilio Cuesta <emiliocuesta@eprosima.com>

* Refs 23515: Apply review

Signed-off-by: Mario Dominguez <mariodominguez@eprosima.com>

---------

Signed-off-by: Emilio Cuesta <emiliocuesta@eprosima.com>
Signed-off-by: Mario Dominguez <mariodominguez@eprosima.com>
Co-authored-by: Mario Dominguez <mariodominguez@eprosima.com>

Author: emiliocuestaf

.github/workflows/mac-ci.yml

@@ -53,5 +53,5 @@ jobs:
       colcon-args: ${{ inputs.colcon-args }}
       cmake-args: '-DSECURITY=ON ${{ inputs.cmake-args }} -DTHIRDPARTY_Asio=FORCE'
       ctest-args: ${{ inputs.ctest-args }}
-      fastdds-branch: ${{ inputs.fastdds_branch || github.ref || 'master' }}
+      fastdds-branch: ${{ inputs.fastdds_branch || github.ref || '3.3.x' }}
       use-ccache: ${{ ((inputs.use-ccache == true) && true) || false }}