How to prevent apache from running PHP in given directory?

I use and need php_fpm7.0 on debian 9 (stretch) apache 2.4.25. DocumentRoot is /var/www/html and works well. Php enabled, scripts executed etc... Now I also want to serve the same arborescence as a filesystem via apache dav_fs module.

To do this :

1. /var/www/webdav is a symlink to /var/www/html so I can name the same directory with 2 different names in apache config file, and so create 2 distinct configurations based on access name
2. I access webdav with /webdav URL. Inside apache config, /webdav is an alias that points to /var/www/webdav. Now I only need to setup the <Directory /var/www/webdav> section and everything should be good.

So far, it almost works : I can get and put files, create directories, rename files etc... with webdav, but PHP files continue to be executed when I GET them via the webdav alias. So if I want to edit a .php file, I indeed get the result of the script in my editor, which is useless.

My setting so far :

<VirtualHost *:80>
    ServerAdmin webmaster@localhost
    DocumentRoot /var/www/html

    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

    <Directory /var/www/html>
        AllowOverride All
        require all granted
        Options Indexes FollowSymLinks MultiViews
    </Directory>

    Alias /webdav /var/www/webdav
    <Directory /var/www/webdav>
        SetHandler none
        Options -ExecCGI -FollowSymLinks -Includes -Indexes -MultiViews
        AddType text/plain php php3 php4 php5 php7 php8 pht phptml phps
        AllowOverride None
        DAV On
        <ifmodule mod_dir.c>
            DirectoryIndex disabled
        </ifmodule>
        <ifmodule mod_rewrite.c>
            RewriteEngine Off
        </ifmodule>
        <Files ~ "^\.ht"> # need to be able to edit .htaccess files.
            require all granted
        </Files>
    </Directory>
</VirtualHost>

What is the correct way to prevent php execution in /var/www/webdav directory ?

Edit and Solution

Since Debian uses SetHandler "proxy:unix:/run/php/php7.0-fpm.sock|fcgi://localhost" /etc/apache2/conf-available/php7.0-fpm.conf, I have to use SetHandler none. But in the <Directory> section, this is too late. it must be used in <Location>, this is interpreted early enough. I also included ProxyPass ! as @exussum suggests (should be placed in <Location> ?). It is useles in this precise case, but proxy is certainly unwanted here anyway.

Also note that I had to put the authentication/authorization in <Directory>. It worked in <Location>, but only the CLI cadaver client could access the webdav collection. When authentication/authorization is in <Directory>, the nautilus filemanager could access the files.

<VirtualHost *:80>
    ServerAdmin webmaster@localhost
    DocumentRoot /var/www/html

    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

    <Directory /var/www/html>
        AllowOverride All
        require all granted
        Options Indexes FollowSymLinks MultiViews
    </Directory>

    Alias /webdav /var/www/webdav
    <Location /webdav>
        <IfModule mod_proxy.c>
            ProxyPass !
        </IfModule>
        SetHandler none
        AddType text/plain php php3 php4 php5 php7 php8 pht phptml phps
    </Location>
    <Directory /var/www/webdav>
        AuthName "Restricted Area"
        AuthType Basic
        AuthUserFile    "/etc/apache2/user-password"
        require valid-user
        Options -ExecCGI -FollowSymLinks -Includes -Indexes -MultiViews
        AllowOverride None
        DAV On
        <ifmodule mod_dir.c>
            DirectoryIndex disabled
        </ifmodule>
        <ifmodule mod_rewrite.c>
            RewriteEngine Off
        </ifmodule>
        <Files ~ "^\.ht"> # need to be able to edit .htaccess files.
            require all granted
        </Files>
    </Directory>
</VirtualHost>