Do not use implicitly nullable parameters and prepare release

ChangeLog.md

@@ -2,6 +2,12 @@
 
 All notable changes are documented in this file using the [Keep a CHANGELOG](http://keepachangelog.com/) principles.
 
+## [3.0.6] - 2023-03-02
+
+### Changed
+
+* Do not use implicitly nullable parameters
+
 ## [3.0.5] - 2023-03-01
 
 * No code changes, only updated `.gitattributes` to not export non-essential files.
@@ -63,6 +69,7 @@ All notable changes are documented in this file using the [Keep a CHANGELOG](htt
 
 * This component is no longer supported on PHP 5.6
 
+[3.0.6]: https://github.com/sebastianbergmann/diff/compare/3.0.5...3.0.6
 [3.0.5]: https://github.com/sebastianbergmann/diff/compare/3.0.4...3.0.5
 [3.0.4]: https://github.com/sebastianbergmann/diff/compare/3.0.3...3.0.4
 [3.0.3]: https://github.com/sebastianbergmann/diff/compare/3.0.2...3.0.3

src/Differ.php

@@ -64,7 +64,7 @@ public function __construct($outputBuilder = null)
      *
      * @return string
      */
-    public function diff($from, $to, LongestCommonSubsequenceCalculator $lcs = null): string
+    public function diff($from, $to, ?LongestCommonSubsequenceCalculator $lcs = null): string
     {
         $diff = $this->diffToArray(
             $this->normalizeDiffInput($from),
@@ -92,7 +92,7 @@ public function diff($from, $to, LongestCommonSubsequenceCalculator $lcs = null)
      *
      * @return array
      */
-    public function diffToArray($from, $to, LongestCommonSubsequenceCalculator $lcs = null): array
+    public function diffToArray($from, $to, ?LongestCommonSubsequenceCalculator $lcs = null): array
     {
         if (\is_string($from)) {
             $from = $this->splitStringByLines($from);

src/Exception/ConfigurationException.php

@@ -24,7 +24,7 @@ public function __construct(
         string $expected,
         $value,
         int $code = 0,
-        \Exception $previous = null
+        ?\Exception $previous = null
     ) {
         parent::__construct(
             \sprintf(