MDL-76429 composer: Bump to phpwebdriver 1.2.1 for php81 compat

This fix is really only required for Moodle 4.1 and up, that will
be the one supporting php81, but we always apply composer changes
to all branches (supported and security), so we keep them running
the same stuff.

Note this comes with a bunch of other small updates, all them
pretty minor and should not be problematic. Better we get them
than keeping them apart.

composer.json

@@ -18,7 +18,7 @@
         "behat/mink-goutte-driver": "^1.3",
         "symfony/process": "^4.0 || ^5.0",
         "behat/behat": "3.11.*",
-        "oleg-andreyev/mink-phpwebdriver": "^1.0.1"
+        "oleg-andreyev/mink-phpwebdriver": "^1.2.1"
     },
     "autoload-dev": {
         "psr-0": {