Clean up output from various tests (#34256)

Tests shouldn't produce extraneous output to the console, but some of
ours were.

* packages/blaze: Prints URLs due to not passing `false` for the
  `$display` parameter to `menu_page_url()`.
* packages/connection: `error_log()` output, which we can redirect to
  /dev/null.
* packages/forms: In CI it prints a bunch of "sh: 1: /usr/sbin/sendmail:
  not found", while locally it doesn't because that exists and it
  **actually sends mail** (to an example.com address, at least, which
  has no MX and so is undeliverable). The 'pre_wp_mail' filter easily
  prevents the sending of mail.
* plugins/jetpack: Output from sync, which we can expect as part of the
  test.

Committed via a GitHub action: https://github.com/Automattic/jetpack/actions/runs/6961138026

CHANGELOG.md

@@ -5,6 +5,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [2.0.3-alpha] - unreleased
+
+This is an alpha version! The changes listed here are not final.
+
 ## [2.0.2] - 2023-11-21
 ### Changed
 - Replaced usage of strpos() with str_contains(). [#34137]
@@ -929,6 +933,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Separate the connection library into its own package.
 
+[2.0.3-alpha]: https://github.com/Automattic/jetpack-connection/compare/v2.0.2...v2.0.3-alpha
 [2.0.2]: https://github.com/Automattic/jetpack-connection/compare/v2.0.1...v2.0.2
 [2.0.1]: https://github.com/Automattic/jetpack-connection/compare/v2.0.0...v2.0.1
 [2.0.0]: https://github.com/Automattic/jetpack-connection/compare/v1.60.1...v2.0.0

src/class-package-version.php

@@ -12,7 +12,7 @@
  */
 class Package_Version {
 
-	const PACKAGE_VERSION = '2.0.2';
+	const PACKAGE_VERSION = '2.0.3-alpha';
 
 	const PACKAGE_SLUG = 'connection';
 

tests/php/test_Server_Sandbox.php

@@ -141,7 +141,12 @@ public function test_server_sandbox( $sandbox_constant, $url, $expected_url, $ex
 		Constants::set_constant( 'JETPACK__SANDBOX_DOMAIN', $sandbox_constant );
 		$headers = array();
 
-		( new Server_Sandbox() )->server_sandbox( $url, $headers );
+		ini_set( 'error_log', '/dev/null' );
+		try {
+			( new Server_Sandbox() )->server_sandbox( $url, $headers );
+		} finally {
+			ini_restore( 'error_log' );
+		}
 
 		$this->assertSame( $expected_url, $url );
 		$this->assertSame( $expected_headers, $headers );
@@ -205,7 +210,12 @@ public function test_server_sandbox_with_xdebug( $url, $expected_url, $add_filte
 			add_filter( 'jetpack_sandbox_add_profile_parameter', '__return_true' );
 		}
 
-		( new Server_Sandbox() )->server_sandbox( $url, $headers, $body, $method );
+		ini_set( 'error_log', '/dev/null' );
+		try {
+			( new Server_Sandbox() )->server_sandbox( $url, $headers, $body, $method );
+		} finally {
+			ini_restore( 'error_log' );
+		}
 
 		$this->assertSame( $expected_url, $url );