bump version number to 2.2.0-a4

CMakeLists.txt

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2c22992..54e6a9f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -290,8 +290,8 @@
     target_sources(picotool PRIVATE get_xip_ram_perms.cpp)
     add_dependencies(picotool generate_otp_header embedded_data)
 endif()
-set(PROJECT_VERSION 2.2.0)
-set(PICOTOOL_VERSION 2.2.0)
+set(PROJECT_VERSION 2.2.0-a4)
+set(PICOTOOL_VERSION 2.2.0-a4)
 set(SYSTEM_VERSION "${CMAKE_SYSTEM_NAME}")
 set(COMPILER_INFO "${CMAKE_C_COMPILER_ID}-${CMAKE_C_COMPILER_VERSION}, ${CMAKE_BUILD_TYPE}")
 target_compile_definitions(picotool PRIVATE

MODULE.bazel

diff --git a/MODULE.bazel b/MODULE.bazel
index 33e41ac..0ceff49 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -1,6 +1,6 @@
 module(
     name = "picotool",
-    version = "2.2.0",
+    version = "2.2.0-a4",
 )
 
 bazel_dep(name = "rules_libusb", version = "0.1.0-rc2")