cmake: bump minimum version to 3.16

Quiets a warning from cmake 3.31.5

This is consistent with the change in webp
https://chromium-review.googlesource.com/c/webm/libwebp/+/6283212

Change-Id: Ic813910fc51ae84c4cfc3f004a503f813e8a5873
(cherry picked from commit 6b04fcd63890b35be5faf17642b54e2b88b64875)
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1ac01d9..6f04312 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -8,11 +8,7 @@
 # License 1.0 was not distributed with this source code in the PATENTS file, you
 # can obtain it at www.aomedia.org/license/patent.
 #
-if(CONFIG_TFLITE)
-  cmake_minimum_required(VERSION 3.11)
-else()
-  cmake_minimum_required(VERSION 3.9)
-endif()
+cmake_minimum_required(VERSION 3.16)
 
 set(AOM_ROOT "${CMAKE_CURRENT_SOURCE_DIR}")
 set(AOM_CONFIG_DIR "${CMAKE_CURRENT_BINARY_DIR}")
diff --git a/build/cmake/dist.cmake b/build/cmake/dist.cmake
index 24db93e..511f34a 100644
--- a/build/cmake/dist.cmake
+++ b/build/cmake/dist.cmake
@@ -8,7 +8,7 @@
 # License 1.0 was not distributed with this source code in the PATENTS file, you
 # can obtain it at www.aomedia.org/license/patent.
 #
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.16)
 
 # Converts spaces in $in_string to semicolons and writes the output to
 # $out_string. In CMake's eyes this converts the input string to a list.
diff --git a/build/cmake/generate_aom_config_templates.cmake b/build/cmake/generate_aom_config_templates.cmake
index 743d007..17e4c2d 100644
--- a/build/cmake/generate_aom_config_templates.cmake
+++ b/build/cmake/generate_aom_config_templates.cmake
@@ -8,7 +8,7 @@
 # License 1.0 was not distributed with this source code in the PATENTS file, you
 # can obtain it at www.aomedia.org/license/patent.
 #
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.16)
 
 string(TIMESTAMP year "%Y")
 set(asm_file_header_block "\;
diff --git a/build/cmake/generate_exports.cmake b/build/cmake/generate_exports.cmake
index 10a6a8f..bab165d 100644
--- a/build/cmake/generate_exports.cmake
+++ b/build/cmake/generate_exports.cmake
@@ -8,7 +8,7 @@
 # License 1.0 was not distributed with this source code in the PATENTS file, you
 # can obtain it at www.aomedia.org/license/patent.
 #
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.16)
 
 # CMAKE_SHARED_LIBRARY_PREFIX can be empty
 set(REQUIRED_ARGS "AOM_ROOT" "AOM_CONFIG_DIR" "AOM_TARGET_SYSTEM" "AOM_SYM_FILE"
diff --git a/build/cmake/pkg_config.cmake b/build/cmake/pkg_config.cmake
index 7fb94e7..88a33a5 100644
--- a/build/cmake/pkg_config.cmake
+++ b/build/cmake/pkg_config.cmake
@@ -8,7 +8,7 @@
 # License 1.0 was not distributed with this source code in the PATENTS file, you
 # can obtain it at www.aomedia.org/license/patent.
 #
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.16)
 
 set(REQUIRED_ARGS "AOM_ROOT" "AOM_CONFIG_DIR" "CMAKE_INSTALL_PREFIX"
                   "CMAKE_INSTALL_BINDIR" "CMAKE_INSTALL_INCLUDEDIR"
diff --git a/build/cmake/version.cmake b/build/cmake/version.cmake
index 24fbf9c..3b2842e 100644
--- a/build/cmake/version.cmake
+++ b/build/cmake/version.cmake
@@ -8,7 +8,7 @@
 # License 1.0 was not distributed with this source code in the PATENTS file, you
 # can obtain it at www.aomedia.org/license/patent.
 #
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.16)
 
 set(REQUIRED_ARGS "AOM_ROOT" "AOM_CONFIG_DIR" "GIT_EXECUTABLE"
                   "PERL_EXECUTABLE")
diff --git a/docs.cmake b/docs.cmake
index 901e8c4..154cb0d 100644
--- a/docs.cmake
+++ b/docs.cmake
@@ -13,7 +13,7 @@
 endif() # AOM_DOCS_CMAKE_
 set(AOM_DOCS_CMAKE_ 1)
 
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.16)
 
 set(AOM_DOXYFILE "${AOM_CONFIG_DIR}/doxyfile")
 set(AOM_DOXYGEN_CONFIG_TEMPLATE "libs.doxy_template")