Fix some tests on WP 4.9

Author: swissspidy

features/plugin-update.feature

@@ -95,7 +95,8 @@ Feature: Update WordPress plugins
       0.5.2
       """
 
-  @require-wp-4.0
+  # Akismet currently requires WordPress 5.8
+  @require-wp-5.8
   Scenario: Update a plugin to its latest minor release
     Given a WP install
     And I run `wp plugin install --force akismet --version=2.5.4`
@@ -196,7 +197,8 @@ Feature: Update WordPress plugins
       Error: Can't find the requested plugin's version 2.5.4 in the WordPress.org plugin repository (HTTP code 404).
       """
 
-  @require-wp-4.7
+  # Akismet currently requires WordPress 5.8
+  @require-wp-5.8
   Scenario: Plugin updates that error should not report a success
     Given a WP install
     And I run `wp plugin install --force akismet --version=4.0`
@@ -223,6 +225,8 @@ Feature: Update WordPress plugins
       Success:
       """
 
+  # Akismet currently requires WordPress 5.8, so there's a warning because of it.
+  @require-wp-5.8
   Scenario: Excluding a missing plugin should not throw an error
     Given a WP install
     And I run `wp plugin update --all --exclude=missing-plugin`

features/plugin.feature

@@ -579,7 +579,8 @@ Feature: Manage WordPress plugins
       """
     And the return code should be 0
 
-  @require-wp-4.7
+  # Akismet currently requires WordPress 5.8, so there's a warning because of it.
+  @require-wp-5.8
   Scenario: Plugin hidden by "all_plugins" filter
     Given a WP install
     And these installed and active plugins: