Attempt to get working under PHP 8.1

- Removed lock file
- Updated test matrix

For reasons behind removing the lock file see:
https://islandora.slack.com/archives/CM5PPAV28/p1659631615201049
Islandora/documentation#1908 (Removal approved)

Instead we'll provide lock files in isle and ansible deployments.

composer.json

@@ -2,17 +2,16 @@
     "type": "project",
     "license": "proprietary",
     "require": {
-        "php": "^7.1.3",
         "ext-ctype": "*",
         "ext-iconv": "*",
         "guzzlehttp/guzzle": "^6.3",
         "monolog/monolog": "^1.24",
-        "symfony/console": "4.2.*",
-        "symfony/dotenv": "4.2.*",
+        "symfony/console": "^4.4",
+        "symfony/dotenv": "^4.4",
         "symfony/flex": "^1.1",
-        "symfony/framework-bundle": "4.2.*",
+        "symfony/framework-bundle": "^4.4",
         "symfony/monolog-bundle": "^3.3",
-        "symfony/yaml": "4.2.*"
+        "symfony/yaml": "^4.4"
     },
     "config": {
         "preferred-install": {
@@ -59,7 +58,7 @@
     "extra": {
         "symfony": {
             "allow-contrib": false,
-            "require": "4.2.*"
+            "require": "^4.4"
         }
     }
 }