Upgrade to PHP 8.1 (#6711)

* Upgrade to PHP 8.1
As discussed in https://github.com/FreshRSS/FreshRSS/discussions/5474

https://www.php.net/releases/8.0/en.php
https://www.php.net/releases/8.1/en.php

Upgrade to available native type declarations
https://php.net/language.types.declarations

Upgrade to https://phpunit.de/announcements/phpunit-10.html which requires PHP 8.1+ (good timing, as version 9 was not maintained anymore)

Upgrade `:oldest` Docker dev image to oldest Alpine version supporting PHP 8.1: Alpine 3.16, which includes PHP 8.1.22.

* Include 6736
https://github.com/FreshRSS/FreshRSS/pull/6736

5 files changed, 7 insertions, 19 deletions

diff --git a/app/Controllers/apiController.php b/app/Controllers/apiController.php
index 7c20b630b..585a7a9bb 100644
--- a/app/Controllers/apiController.php
+++ b/app/Controllers/apiController.php
@@ -9,9 +9,8 @@ class FreshRSS_api_Controller extends FreshRSS_ActionController {
 	/**
 	 * Update the user API password.
 	 * Return an error message, or `false` if no error.
-	 * @return false|string
 	 */
-	public static function updatePassword(string $apiPasswordPlain) {
+	public static function updatePassword(string $apiPasswordPlain): string|false {
 		$username = Minz_User::name();
 		if ($username == null) {
 			return _t('feedback.api.password.failed');
diff --git a/app/Controllers/configureController.php b/app/Controllers/configureController.php
index 385bd1e2e..a9304376f 100644
--- a/app/Controllers/configureController.php
+++ b/app/Controllers/configureController.php
@@ -479,8 +479,6 @@ class FreshRSS_configure_Controller extends FreshRSS_ActionController {
 	 *   - user category limit (default: 16384)
 	 *   - user feed limit (default: 16384)
 	 *   - user login duration for form auth (default: FreshRSS_Auth::DEFAULT_COOKIE_DURATION)
-	 *
-	 * The `force-email-validation` is ignored with PHP < 5.5
 	 */
 	public function systemAction(): void {
 		if (!FreshRSS_Auth::hasAccess('admin')) {
diff --git a/app/Controllers/feedController.php b/app/Controllers/feedController.php
index dbdf858a7..42639f5e1 100644
--- a/app/Controllers/feedController.php
+++ b/app/Controllers/feedController.php
@@ -755,7 +755,7 @@ class FreshRSS_feed_Controller extends FreshRSS_ActionController {
 	 * @param int $nbNewEntries The number of top recent entries to process.
 	 * @return int|false The number of new labels added, or false in case of error.
 	 */
-	private static function applyLabelActions(int $nbNewEntries) {
+	private static function applyLabelActions(int $nbNewEntries): int|false {
 		$tagDAO = FreshRSS_Factory::createTagDao();
 		$labels = FreshRSS_Context::labels();
 		$labels = array_filter($labels, static function (FreshRSS_Tag $label) {
diff --git a/app/Controllers/importExportController.php b/app/Controllers/importExportController.php
index 2dc25fa2f..c4f64337b 100644
--- a/app/Controllers/importExportController.php
+++ b/app/Controllers/importExportController.php
@@ -33,10 +33,7 @@ class FreshRSS_importExport_Controller extends FreshRSS_ActionController {
 		FreshRSS_View::prependTitle(_t('sub.import_export.title') . ' · ');
 	}
 
-	/**
-	 * @return float|int|string
-	 */
-	private static function megabytes(string $size_str) {
+	private static function megabytes(string $size_str): float|int|string {
 		switch (substr($size_str, -1)) {
 			case 'M':
 			case 'm':
@@ -51,10 +48,7 @@ class FreshRSS_importExport_Controller extends FreshRSS_ActionController {
 		return $size_str;
 	}
 
-	/**
-	 * @param string|int $mb
-	 */
-	private static function minimumMemory($mb): void {
+	private static function minimumMemory(int|string $mb): void {
 		$mb = (int)$mb;
 		$ini = self::megabytes(ini_get('memory_limit') ?: '0');
 		if ($ini < $mb) {
@@ -240,11 +234,8 @@ class FreshRSS_importExport_Controller extends FreshRSS_ActionController {
 		return 'unknown';
 	}
 
-	/**
-	 * @return false|string
-	 */
-	private function ttrssXmlToJson(string $xml) {
-		$table = (array)simplexml_load_string($xml, null, LIBXML_NOBLANKS | LIBXML_NOCDATA);
+	private function ttrssXmlToJson(string $xml): string|false {
+		$table = (array)simplexml_load_string($xml, options: LIBXML_NOBLANKS | LIBXML_NOCDATA);
 		$table['items'] = $table['article'] ?? [];
 		unset($table['article']);
 		for ($i = count($table['items']) - 1; $i >= 0; $i--) {
diff --git a/app/Controllers/updateController.php b/app/Controllers/updateController.php
index f07ed338b..e5bf276cd 100644
--- a/app/Controllers/updateController.php
+++ b/app/Controllers/updateController.php
@@ -93,7 +93,7 @@ class FreshRSS_update_Controller extends FreshRSS_ActionController {
 	}
 
 	/** @return string|true */
-	public static function gitPull() {
+	public static function gitPull(): string|bool {
 		Minz_Log::notice(_t('admin.update.viaGit'));
 		$cwd = getcwd();
 		if ($cwd === false) {