Docs: improve type declarations

This commit addresses the `@return` tag for all sniff `register()` methods. Future commits may follow for other parts of the codebase.

PHP native tokens will always be integers.
PHP_CodeSniffer polyfilled and PHP_CodeSniffer native tokens will always be strings.

While some sniffs only return one or the other, I've chosen to update these tags to be the same across all sniffs for consistency.

Author: jrfnl

src/Sniffs/AbstractArraySniff.php

@@ -19,7 +19,7 @@ abstract class AbstractArraySniff implements Sniff
     /**
      * Returns an array of tokens this test wants to listen for.
      *
-     * @return array
+     * @return array<int|string>
      */
     final public function register()
     {

src/Sniffs/AbstractPatternSniff.php

@@ -78,7 +78,7 @@ public function __construct($ignoreComments=null)
      * Classes extending <i>AbstractPatternTest</i> should implement the
      * <i>getPatterns()</i> method to register the patterns they wish to test.
      *
-     * @return int[]
+     * @return array<int|string>
      * @see    process()
      */
     final public function register()

src/Sniffs/AbstractScopeSniff.php

@@ -104,7 +104,7 @@ public function __construct(
      * DO NOT OVERRIDE THIS METHOD. Use the constructor of this class to register
      * for the desired tokens and scope.
      *
-     * @return int[]
+     * @return array<int|string>
      * @see    __constructor()
      */
     final public function register()

src/Sniffs/Sniff.php

@@ -28,13 +28,13 @@ interface Sniff
      *
      * <code>
      *    return array(
-     *            T_WHITESPACE,
-     *            T_DOC_COMMENT,
-     *            T_COMMENT,
-     *           );
+     *        T_WHITESPACE,
+     *        T_DOC_COMMENT,
+     *        T_COMMENT,
+     *    );
      * </code>
      *
-     * @return mixed[]
+     * @return array<int|string>
      * @see    Tokens.php
      */
     public function register();

src/Standards/Generic/Sniffs/Arrays/DisallowLongArraySyntaxSniff.php

@@ -19,7 +19,7 @@ class DisallowLongArraySyntaxSniff implements Sniff
     /**
      * Registers the tokens that this sniff wants to listen for.
      *
-     * @return int[]
+     * @return array<int|string>
      */
     public function register()
     {

src/Standards/Generic/Sniffs/Classes/DuplicateClassNameSniff.php

@@ -26,7 +26,7 @@ class DuplicateClassNameSniff implements Sniff
     /**
      * Registers the tokens that this sniff wants to listen for.
      *
-     * @return int[]
+     * @return array<int|string>
      */
     public function register()
     {

src/Standards/Generic/Sniffs/Classes/OpeningBraceSameLineSniff.php

@@ -19,7 +19,7 @@ class OpeningBraceSameLineSniff implements Sniff
     /**
      * Returns an array of tokens this test wants to listen for.
      *
-     * @return array
+     * @return array<int|string>
      */
     public function register()
     {

src/Standards/Generic/Sniffs/CodeAnalysis/AssignmentInConditionSniff.php

@@ -40,7 +40,7 @@ class AssignmentInConditionSniff implements Sniff
     /**
      * Registers the tokens that this sniff wants to listen for.
      *
-     * @return int[]
+     * @return array<int|string>
      */
     public function register()
     {

src/Standards/Generic/Sniffs/CodeAnalysis/EmptyPHPStatementSniff.php

@@ -23,7 +23,7 @@ class EmptyPHPStatementSniff implements Sniff
     /**
      * Returns an array of tokens this test wants to listen for.
      *
-     * @return int[]
+     * @return array<int|string>
      */
     public function register()
     {

src/Standards/Generic/Sniffs/CodeAnalysis/EmptyStatementSniff.php

@@ -34,7 +34,7 @@ class EmptyStatementSniff implements Sniff
     /**
      * Registers the tokens that this sniff wants to listen for.
      *
-     * @return int[]
+     * @return array<int|string>
      */
     public function register()
     {