Fix duplicated entry for page_cache.page_cancelled_faults metric

There is a duplicated entry for that metric, with the only difference being one has the description spelled `canceled` and the other one `cancelled`.

I merged both into the first entry just because because that matches the order of the metrics in the code-base.

modules/ROOT/pages/monitoring/metrics/reference.adoc

@@ -214,11 +214,10 @@ By default, database metrics include:
 |<prefix>.page_cache.evictions.cooperative|The total number of cooperative page evictions executed by the page cache due to low available pages. (counter)
 |<prefix>.page_cache.page_faults|The total number of page faults in the page cache. If this count keeps increasing over time, it may indicate that more page cache is required. However, note that when Neo4j Enterprise starts up, all page cache warmup activities result in page faults. Therefore, it is normal to observe a significant page fault count immediately after startup. (counter)
 |<prefix>.page_cache.page_fault_failures|The total number of failed page faults happened in the page cache. (counter)
-|<prefix>.page_cache.page_cancelled_faults|The total number of canceled page faults happened in the page cache. (counter)
+|<prefix>.page_cache.page_cancelled_faults|The total number of cancelled page faults happened in the page cache. (counter)
 |<prefix>.page_cache.page_vectored_faults|The total number of vectored page faults happened in the page cache. (counter)
 |<prefix>.page_cache.page_vectored_faults_failures|The total number of failed vectored page faults happened in the page cache. (counter)
 |<prefix>.page_cache.page_no_pin_page_faults|The total number of page faults that are not caused by the page pins happened in the page cache. Represent pages loaded by the vectored faults (counter)
-|<prefix>.page_cache.page_cancelled_faults|The total number of cancelled page faults happened in the page cache. (counter)
 |<prefix>.page_cache.hits|The total number of page hits happened in the page cache. (counter)
 |<prefix>.page_cache.hit_ratio|The ratio of hits to the total number of lookups in the page cache. Performance relies on efficiently using the page cache, so this metric should be in the 98-100% range consistently. If it is much lower than that, then the database is going to disk too often. (gauge)
 |<prefix>.page_cache.usage_ratio|The ratio of number of used pages to total number of available pages. This metric shows what percentage of the allocated page cache is actually being used. If it is 100%, then it is likely that the hit ratio will start dropping, and you should consider allocating more RAM to page cache. (gauge)