[CMSP-942] PHP < 7.2 EOS (#8896)

* [CMSP-942] PHP < 7.2 EOS

* Apply suggestions from code review

* Update 2024-03-18-PHP-7-1-EOS.md

* Update 2024-03-18-PHP-7-1-EOS.md

* adjust site creation language

* Update source/releasenotes/2024-03-18-PHP-7-1-EOS.md

* relative path for docs

* Adjust PHP EoS language in primary PHP Doc

* note in php docs

* make alert a footnote

* Try without calling so much attention

* extra space

* Apply suggestions from code review

Co-authored-by: Chris Reynolds <[email protected]>

* hmtl not markdown

* bump date

* line break

* directions are hard

* Update source/content/guides/php/01-introduction.md

---------

Co-authored-by: Ingrid <[email protected]>
Co-authored-by: Chris Reynolds <[email protected]>

source/content/guides/php/01-introduction.md

@@ -32,17 +32,15 @@ Click the links below to display complete PHP information for each version, incl
 | [7.4](https://v74-php-info.pantheonsite.io/)     | <span style="color:green">✔</span>         | ❌          |
 | [7.3](https://v73-php-info.pantheonsite.io/)     | <span style="color:green">✔</span>         | ❌           |
 | [7.2](https://v72-php-info.pantheonsite.io/)     | <span style="color:green">✔</span>         | ❌           |
-| [7.1](https://v71-php-info.pantheonsite.io/)     | <span style="color:green">✔</span>          | ❌           |
-| [7.0](https://v70-php-info.pantheonsite.io/)     | <span style="color:green">✔</span>         | ❌           |
-| [5.6](https://v56-php-info.pantheonsite.io/)     | <span style="color:green">✔</span>         | ❌           |
+| [7.1](https://v71-php-info.pantheonsite.io/) <sup>2</sup>   | <span style="color:green">✔</span>          | ❌           |
+| [7.0](https://v70-php-info.pantheonsite.io/) <sup>2</sup>   | <span style="color:green">✔</span>         | ❌           |
+| [5.6](https://v56-php-info.pantheonsite.io/) <sup>2</sup>   | <span style="color:green">✔</span>         | ❌           |
 
-Sites that run older PHP versions not listed above will continue to serve pages. However, new development cannot be done because the development environment behavior is undefined and no longer supported. You can [upgrade your PHP version](/guides/php/php-versions) in the development environment to resume development on your site.
+Sites that run older PHP versions not listed above will continue to serve pages. While older sites will still run unlisted and unsupported versions of PHP, new sites cannot change their PHP version to unsupported values. You can [upgrade your PHP version](/guides/php/php-versions) in the development environment to resume development on your site.
 
-<Alert title="PHP 8.3 New Relic compatibility" type="info">
+<p><sup>1</sup> Currently, PHP 8.3 on Pantheon does not support New Relic. As such, you will not be able to view your New Relic dashboard on any site that has been updated to PHP 8.3. We will be updating our platform to support New Relic on PHP 8.3 sites soon.</p>
 
-<sup>1</sup> Currently, New Relic does not support PHP 8.3. As such, you will not be able to view your New Relic dashboard on any site that has been updated to PHP 8.3. We will be updating our platform to support New Relic on PHP 8.3 sites as soon as a compatible New Relic release is available to us.
-
-</Alert>
+<p><sup>2</sup> On May 15, 2024, PHP 5.6, 7.0, and 7.1 will reach "End of Sale" and be removed from the supported PHP versions. New sites will not support PHP versions older than 7.2. For more details, see <a href="/release-notes/2024/03/PHP-7-1-EOS">this release note</a>.</p>
 
 ## Drush Compatibility
 

source/releasenotes/2024-03-20-PHP-7-1-EOS.md

@@ -0,0 +1,14 @@
+---
+title: "PHP versions below 7.2 to reach end-of-sale"
+published_date: "2024-03-20"
+categories: [infrastructure, security, action-required]
+---
+As part of our continued effort to provide the latest and best in secure software, PHP versions 7.1 and below will reach end-of-sale (EoS) on May 15, 2024. This means that sites created after May 15 will not be able to change their PHP version to PHP 7.1, 7.0, or any version of PHP 5. Sites created with custom upstreams using EoS PHP may also have unexpected behavior upon site creation.
+
+Sites already running PHP 5, PHP 7.0, or PHP 7.1 will continue to run even after May 15.
+
+PHP 7.1 was declared end-of-life (EoL) by [the PHP Foundation](https://www.php.net/supported-versions.php) on November 30, 2020, more than three years ago. PHP 5.6 reached EoL on December 31, 2018, more than five years ago. EoL software does not receive security or feature updates, and could expose sites to attack if any vulnerabilities or exploits are discovered.
+
+**Action required**
+
+Customers using custom upstreams with a PHP version less than 7.2 should update their custom upstreams by May 15 to avoid disruption. The current supported versions of PHP are 8.1, 8.2, and 8.3. Pantheon [currently recommends](/guides/php#supported-php-versions) at least PHP 8.1 for all production sites.