Bump default devenv Python to 3.10 (#12951)

dev/start

@@ -44,7 +44,7 @@ cleanup
 _SRC="$(cd "$(dirname "$(dirname "${BASH_SOURCE:-$0}")")" 2>&1 > /dev/null; pwd -P)"
 
 # define default values
-_DEFAULT_PYTHON="3.8"
+_DEFAULT_PYTHON="3.10"
 # $ uname -sm
 # Linux x86_64
 # Linux aarch64
@@ -126,7 +126,7 @@ while [ $# -gt 0 ]; do
 done
 
 # fallback to default values
-_PYTHON="${_PYTHON:-3.8}"
+_PYTHON="${_PYTHON:-3.10}"
 # $ uname -sm
 # Linux x86_64
 # Linux aarch64

dev/start.bat

@@ -41,7 +41,7 @@
     @ECHO Usage: %_SCRIPT% [options]
     @ECHO.
     @ECHO Options:
-    @ECHO   /P  VERSION  Python version for the env to activate. ^(default: 3.8^)
+    @ECHO   /P  VERSION  Python version for the env to activate. ^(default: 3.10^)
     @ECHO   /U           Force update packages. ^(default: update every 24 hours^)
     @ECHO   /D  PATH     Path to base env install, can also be defined in ~\.condarc.
     @ECHO                Path is appended with Windows. ^(default: devenv^)
@@ -54,7 +54,7 @@
 :ARGS_END
 
 @REM fallback to default values
-@IF "%_PYTHON%"=="" @SET "_PYTHON=3.8"
+@IF "%_PYTHON%"=="" @SET "_PYTHON=3.10"
 @IF "%_UPDATE%"=="" @SET "_UPDATE=1"
 @IF "%_DRYRUN%"=="" @SET "_DRYRUN=1"