docs: replace broken links for older GUC settings

Use wayback machine links for the PostgREST v8.0 docs

docs/api.rst

@@ -2829,7 +2829,7 @@ You can access request headers, cookies and JWT claims by reading GUC variables
 Legacy GUC variable names
 ~~~~~~~~~~~~~~~~~~~~~~~~~
 
-For PostgreSQL versions below 14, PostgREST will take into consideration the :ref:`db-use-legacy-gucs` config, which is set to true by default. This means that the interface for accessing these GUCs is `the same as in older versions <https://postgrest.org/en/v8.0/api.html#accessing-request-headers-cookies-and-jwt-claims>`_. You can opt in to use the JSON GUCs mentioned above by setting the ``db-use-legacy-gucs`` to false.
+For PostgreSQL versions below 14, PostgREST will take into consideration the :ref:`db-use-legacy-gucs` config, which is set to true by default. This means that the interface for accessing these GUCs is `the same as in older versions <https://web.archive.org/web/20230326043738/https://postgrest.org/en/v8.0/api.html#accessing-request-headers-cookies-and-jwt-claims>`_. You can opt in to use the JSON GUCs mentioned above by setting the ``db-use-legacy-gucs`` to false.
 
 .. _guc_req_path_method:
 

docs/configuration.rst

@@ -477,7 +477,7 @@ db-use-legacy-gucs
   **In-Database** pgrst.db_use_legacy_gucs
   =============== =================
 
-  Determine if GUC request settings for headers, cookies and jwt claims use the `legacy names <https://postgrest.org/en/v8.0/api.html#accessing-request-headers-cookies-and-jwt-claims>`_ (string with dashes, invalid starting from PostgreSQL v14) with text values instead of the :ref:`new names <guc_req_headers_cookies_claims>` (string without dashes, valid on all PostgreSQL versions) with json values.
+  Determine if GUC request settings for headers, cookies and jwt claims use the `legacy names <https://web.archive.org/web/20230326043738/https://postgrest.org/en/v8.0/api.html#accessing-request-headers-cookies-and-jwt-claims>`_ (string with dashes, invalid starting from PostgreSQL v14) with text values instead of the :ref:`new names <guc_req_headers_cookies_claims>` (string without dashes, valid on all PostgreSQL versions) with json values.
 
   On PostgreSQL versions 14 and above, this parameter is ignored.
 

docs/releases/v9.0.0.rst

@@ -10,7 +10,7 @@ Features
 PostgreSQL 14 compatibility
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-PostgreSQL 14 Beta 1 tightened its GUC naming scheme making it impossible to use multiple dots (``.``) and dashes (``-``) on custom GUC parameters, this caused our `old HTTP Context <https://postgrest.org/en/v8.0/api.html#accessing-request-headers-cookies-and-jwt-claims>`_ to fail across all requests. Thankfully, `@robertsosinski <https://github.com/robertsosinski>`_ got the PostgreSQL team to reconsider allowing multiple dots in the GUC name, allowing us to avoid a major breaking change. You can see the full discussion `here <https://www.postgresql.org/message-id/17045-6a4a9f0d1513f72b%40postgresql.org>`_.
+PostgreSQL 14 Beta 1 tightened its GUC naming scheme making it impossible to use multiple dots (``.``) and dashes (``-``) on custom GUC parameters, this caused our `old HTTP Context <https://web.archive.org/web/20230326043738/https://postgrest.org/en/v8.0/api.html#accessing-request-headers-cookies-and-jwt-claims>`_ to fail across all requests. Thankfully, `@robertsosinski <https://github.com/robertsosinski>`_ got the PostgreSQL team to reconsider allowing multiple dots in the GUC name, allowing us to avoid a major breaking change. You can see the full discussion `here <https://www.postgresql.org/message-id/17045-6a4a9f0d1513f72b%40postgresql.org>`_.
 
 Still, dashes cannot be used on PostgreSQL 14 custom GUC parameters, so we changed our HTTP Context :ref:`to namespace using a mix of dots and JSON <guc_req_headers_cookies_claims>`. On older PostgreSQL versions we still use the :ref:`guc_legacy_names`. If you wish to use the new JSON GUCs on these versions, set the :ref:`db-use-legacy-gucs` config option to false.