Change default python branch from 'main' to 'master' (#6325)

Signed-off-by: Miguel Company <miguelcompany@eprosima.com>

Author: MiguelCompany

.github/workflows/reusable-ubuntu-ci.yml

@@ -61,7 +61,7 @@ on:
 env:
   security-cmake-flag: ${{ inputs.security == true && '-DSECURITY=ON' || '-DSECURITY=OFF' }}
   colcon-build-default-cmake-args: '-DCMAKE_CXX_FLAGS_INIT="-Werror -Wunused-value -Woverloaded-virtual -Wsign-compare -Wcast-align -Wlogical-op -Wduplicated-cond -Wrestrict -Wpointer-arith -Wwrite-strings -Wunreachable-code"'
-  fastdds-python-branch: 'main'
+  fastdds-python-branch: 'master'
   fastdds-docs-branch: 'master'
   shapes-demo-branch: 'master'
   discovery-server-branch: 'master'