Spelling improvements, in comments only

FossilOrigin-Name: 9ee25eeaf17124dbe34b961384e74c1ae239ee1798bb01907938600ed6b4066f

src/sqlite.h.in

@@ -2302,7 +2302,7 @@ struct sqlite3_mem_methods {
 ** database handle, SQLite checks if this will mean that there are now no
 ** connections at all to the database. If so, it performs a checkpoint
 ** operation before closing the connection. This option may be used to
-** override this behaviour. The first parameter passed to this operation
+** override this behavior. The first parameter passed to this operation
 ** is an integer - positive to disable checkpoints-on-close, or zero (the
 ** default) to enable them, and negative to leave the setting unchanged.
 ** The second parameter is a pointer to an integer
@@ -7765,7 +7765,7 @@ int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
 ** code is returned and the transaction rolled back.
 **
 ** Calling this function with an argument that is not a NULL pointer or an
-** open blob handle results in undefined behaviour. ^Calling this routine
+** open blob handle results in undefined behavior. ^Calling this routine
 ** with a null pointer (such as would be returned by a failed call to
 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
 ** is passed a valid open blob handle, the values returned by the
@@ -9307,8 +9307,8 @@ int sqlite3_backup_pagecount(sqlite3_backup *p);
 ** blocked connection already has a registered unlock-notify callback,
 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
 ** called with a NULL pointer as its second argument, then any existing
-** unlock-notify callback is cancelled. ^The blocked connections
-** unlock-notify callback may also be cancelled by closing the blocked
+** unlock-notify callback is canceled. ^The blocked connections
+** unlock-notify callback may also be canceled by closing the blocked
 ** connection using [sqlite3_close()].
 **
 ** The unlock-notify callback is not reentrant. If an application invokes