tools: Increase the minimal supported CMake version to 3.16

This updates the minimal supported version of CMake to 3.16, which in turn enables us to use more CMake features and have a cleaner build system.
This is the version that provides most new features and also the one we use in our latest docker image for CI.

examples/zigbee/esp_zigbee_gateway/CMakeLists.txt

@@ -2,6 +2,6 @@
 # https://docs.espressif.com/projects/esp-idf/en/latest/api-guides/build-system.html
 # The following five lines of boilerplate have to be in your project's
 # CMakeLists in this exact order for cmake to work correctly
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.16)
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 project(esp_zigbee_gateway)

examples/zigbee/esp_zigbee_rcp/CMakeLists.txt

@@ -2,6 +2,6 @@
 # https://docs.espressif.com/projects/esp-idf/en/latest/api-guides/build-system.html
 # The following five lines of boilerplate have to be in your project's
 # CMakeLists in this exact order for cmake to work correctly
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.16)
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 project(esp_zigbee_rcp)

examples/zigbee/light_sample/light_bulb/CMakeLists.txt

@@ -1,6 +1,6 @@
 # The following lines of boilerplate have to be in your project's CMakeLists
 # in this exact order for cmake to work correctly
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.16)
 set(EXTRA_COMPONENT_DIRS
     $ENV{IDF_PATH}/examples/common_components/led_strip
     )

examples/zigbee/light_sample/light_coordinator/CMakeLists.txt

@@ -1,5 +1,5 @@
 # The following lines of boilerplate have to be in your project's CMakeLists
 # in this exact order for cmake to work correctly
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.16)
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 project(light_coordinator)

examples/zigbee/light_sample/light_switch/CMakeLists.txt

@@ -1,5 +1,5 @@
 # The following lines of boilerplate have to be in your project's CMakeLists
 # in this exact order for cmake to work correctly
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.16)
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 project(light_switch)