minor #33020 [Intl] fix nullable phpdocs and useless method visibility of internal class (Tobion)

This PR was merged into the 3.4 branch.

Discussion
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[Intl] fix nullable phpdocs and useless method visibility of internal class

| Q             | A
| ------------- | ---
| Branch?       | 3.4
| Bug fix?      | no
| New feature?  | no <!-- please update src/**/CHANGELOG.md files -->
| BC breaks?    | no     <!-- see https://symfony.com/bc -->
| Deprecations? | no <!-- please update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tests pass?   | yes    <!-- please add some, will be required by reviewers -->
| Fixed tickets |
| License       | MIT
| Doc PR        |

Fix stuff found in #32525

Commits
-------

63b71b5ade [Intl] fix nullable phpdocs and useless method visibility of internal class

Author: nicolas-grekas

Collator/Collator.php

@@ -70,7 +70,7 @@ class Collator
     const SORT_STRING = 1;
 
     /**
-     * @param string $locale The locale code. The only currently supported locale is "en" (or null using the default locale, i.e. "en")
+     * @param string|null $locale The locale code. The only currently supported locale is "en" (or null using the default locale, i.e. "en")
      *
      * @throws MethodArgumentValueNotImplementedException When $locale different than "en" or null is passed
      */
@@ -84,7 +84,7 @@ public function __construct($locale)
     /**
      * Static constructor.
      *
-     * @param string $locale The locale code. The only currently supported locale is "en" (or null using the default locale, i.e. "en")
+     * @param string|null $locale The locale code. The only currently supported locale is "en" (or null using the default locale, i.e. "en")
      *
      * @return self
      *

DateFormatter/IntlDateFormatter.php

@@ -118,7 +118,7 @@ class IntlDateFormatter
     private $timeZoneId;
 
     /**
-     * @param string                                  $locale   The locale code. The only currently supported locale is "en" (or null using the default locale, i.e. "en")
+     * @param string|null                             $locale   The locale code. The only currently supported locale is "en" (or null using the default locale, i.e. "en")
      * @param int|null                                $datetype Type of date formatting, one of the format type constants
      * @param int|null                                $timetype Type of time formatting, one of the format type constants
      * @param \IntlTimeZone|\DateTimeZone|string|null $timezone Timezone identifier
@@ -152,7 +152,7 @@ public function __construct($locale, $datetype, $timetype, $timezone = null, $ca
     /**
      * Static constructor.
      *
-     * @param string                                  $locale   The locale code. The only currently supported locale is "en" (or null using the default locale, i.e. "en")
+     * @param string|null                             $locale   The locale code. The only currently supported locale is "en" (or null using the default locale, i.e. "en")
      * @param int|null                                $datetype Type of date formatting, one of the format type constants
      * @param int|null                                $timetype Type of time formatting, one of the format type constants
      * @param \IntlTimeZone|\DateTimeZone|string|null $timezone Timezone identifier

NumberFormatter/NumberFormatter.php

@@ -241,13 +241,13 @@ class NumberFormatter
     ];
 
     /**
-     * @param string $locale  The locale code. The only currently supported locale is "en" (or null using the default locale, i.e. "en")
-     * @param int    $style   Style of the formatting, one of the format style constants.
-     *                        The only supported styles are NumberFormatter::DECIMAL
-     *                        and NumberFormatter::CURRENCY.
-     * @param string $pattern Not supported. A pattern string in case $style is NumberFormat::PATTERN_DECIMAL or
-     *                        NumberFormat::PATTERN_RULEBASED. It must conform to  the syntax
-     *                        described in the ICU DecimalFormat or ICU RuleBasedNumberFormat documentation
+     * @param string|null $locale  The locale code. The only currently supported locale is "en" (or null using the default locale, i.e. "en")
+     * @param int         $style   Style of the formatting, one of the format style constants.
+     *                             The only supported styles are NumberFormatter::DECIMAL
+     *                             and NumberFormatter::CURRENCY.
+     * @param string      $pattern Not supported. A pattern string in case $style is NumberFormat::PATTERN_DECIMAL or
+     *                             NumberFormat::PATTERN_RULEBASED. It must conform to  the syntax
+     *                             described in the ICU DecimalFormat or ICU RuleBasedNumberFormat documentation
      *
      * @see http://www.php.net/manual/en/numberformatter.create.php
      * @see http://www.icu-project.org/apiref/icu4c/classDecimalFormat.html#_details