[DOCS] Remove shrink snippet from 'Size your shards' (elastic#77593)

The current shrink API snippet doesn't show you how to remove replicas or reduce primary shards.

Rather than duplicate those instructions from the shrink API docs, this removes the snippet. A link to the shrink API and shrink ILM action docs is already provided.

It also updates a delete index API snippet to avoid wildcards. Wildcard expansion for the delete index API is disabled by default in 8.0.

Author: jrodewig

docs/reference/how-to/size-your-shards.asciidoc

@@ -255,7 +255,7 @@ unneeded indices.
 
 [source,console]
 ----
-DELETE my-index-*
+DELETE my-index-000001
 ----
 // TEST[setup:my_index]
 
@@ -281,12 +281,6 @@ POST my-index-000001/_forcemerge
 If you no longer write to an index, you can use the
 <<indices-shrink-index,shrink index API>> to reduce its shard count.
 
-[source,console]
-----
-POST my-index-000001/_shrink/my-shrunken-index-000001
-----
-// TEST[s/^/PUT my-index-000001\n{"settings":{"index.number_of_shards":2,"blocks.write":true}}\n/]
-
 {ilm-init} also has a <<ilm-shrink,shrink action>> for indices in the
 warm phase.