[DOCS] Remove [testenv="gold+"] attributes (#79309)

Changes:

* Removes several `[testenv="gold+"]` attributes from the docs. `gold+` is not a valid [subscription level](https://www.elastic.co/subscriptions) or testenv value.
* Moves two `[testenv="basic"]` attributes to the file header. This makes the `testenv` placement consistent and fixes the yml file generated from `docs/reference/snapshot-restore/register-repository.asciidoc`.

Co-authored-by: James Rodewig <40268737+jrodewig@users.noreply.github.com>

docs/reference/commands/certgen.asciidoc

@@ -1,5 +1,3 @@
-[role="xpack"]
-[testenv="gold+"]
 [[certgen]]
 == elasticsearch-certgen
 

docs/reference/commands/certutil.asciidoc

@@ -1,5 +1,3 @@
-[role="xpack"]
-[testenv="gold+"]
 [[certutil]]
 == elasticsearch-certutil
 

docs/reference/commands/croneval.asciidoc

@@ -1,5 +1,3 @@
-[role="xpack"]
-[testenv="gold+"]
 [[elasticsearch-croneval]]
 == elasticsearch-croneval
 

docs/reference/commands/saml-metadata.asciidoc

@@ -1,5 +1,3 @@
-[role="xpack"]
-[testenv="gold+"]
 [[saml-metadata]]
 == elasticsearch-saml-metadata
 

docs/reference/commands/service-tokens-command.asciidoc

@@ -1,5 +1,3 @@
-[role="xpack"]
-[testenv="gold+"]
 [[service-tokens-command]]
 == elasticsearch-service-tokens
 

docs/reference/commands/setup-passwords.asciidoc

@@ -1,5 +1,3 @@
-[role="xpack"]
-[testenv="gold+"]
 [[setup-passwords]]
 == elasticsearch-setup-passwords
 

docs/reference/commands/syskeygen.asciidoc

@@ -1,5 +1,3 @@
-[role="xpack"]
-[testenv="gold+"]
 [[syskeygen]]
 == elasticsearch-syskeygen
 

docs/reference/commands/users-command.asciidoc

@@ -1,5 +1,3 @@
-[role="xpack"]
-[testenv="gold+"]
 [[users-command]]
 == elasticsearch-users