Merge branch 'php_updates' into 'master'

Update ESR Reference in the PHP requirements table and update php...

See merge request !38

docs/general/requirements.md

@@ -65,10 +65,11 @@ It is also important to ensure that the same PHP extensions/modules are loaded o
 
 ### PHP Version
 
-| | CiviCRM 5.33 ESR | CiviCRM 5.x.x stable |
+| | CiviCRM 5.39 ESR | CiviCRM 5.x.x stable |
 | ---- | ---- | ---- |
-| PHP 8.0 | **incompatible** | compatible from CiviCRM 5.39 however not **recommended** yet until the extension ecosystem catches up. |
-| PHP 7.4 | **incompatible** | compatible and **recommended** from CiviCRM 5.37 onwards. |
+| PHP 8.1 | **incompatible** | **incompatible** as not yet confirmed to work on test matrix |
+| PHP 8.0 | compatible however not **recommended** yet until the extension ecosystem catches up. | compatible from CiviCRM 5.39 however not **recommended** yet until the extension ecosystem catches up. |
+| PHP 7.4 | compatible and **recommended** | compatible and **recommended** |
 | PHP 7.3 | compatible and **recommended** | compatible and **recommended** |
 | PHP 7.2 | compatible and **recommended** - but see note below about resaving the SMTP password | compatible and **recommended** but see note below about resaving the SMTP password |
 | PHP 7.1 | compatible but **not recommended** due to to [PHP end-of life](http://php.net/eol.php) in Dec 2019 | **incompatible** as of 5.35.0 |
@@ -87,7 +88,8 @@ It is also important to ensure that the same PHP extensions/modules are loaded o
     | 5.24                     | 7.0                 | 7.3                     |
     | 5.25 - 5.34              | 7.1                 | 7.3                     |
     | 5.35 - 5.36              | 7.2                 | 7.3                     |
-    | 5.37 - Current           | 7.2                 | 7.4                     |
+    | 5.37 - 5.45              | 7.2                 | 7.4                     |
+    | 5.46 - current           | 7.3                 | 7.4                     |
 
 ### PHP Extensions