Org writer: don't add blank line before lists.

The code to do this was apparently copied over from the RST
writer, but these blank lines aren't necessary or desirable
in org.  See #7810 comment 3.

src/Text/Pandoc/Writers/Org.hs

@@ -197,9 +197,7 @@ blockToOrg (Table _ blkCapt specs thead tbody tfoot) =  do
   return $ head'' $$ body $$ caption $$ blankline
 blockToOrg (BulletList items) = do
   contents <- mapM bulletListItemToOrg items
-  -- ensure that sublists have preceding blank line
-  return $ blankline $$
-           (if isTightList items then vcat else vsep) contents $$
+  return $ (if isTightList items then vcat else vsep) contents $$
            blankline
 blockToOrg (OrderedList (start, _, delim) items) = do
   let delim' = case delim of
@@ -210,9 +208,7 @@ blockToOrg (OrderedList (start, _, delim) items) = do
       counters = (case start of 1 -> Nothing; n -> Just n) : repeat Nothing
   contents <- zipWithM (\x f -> f x) items $
               zipWith orderedListItemToOrg markers counters
-  -- ensure that sublists have preceding blank line
-  return $ blankline $$
-           (if isTightList items then vcat else vsep) contents $$
+  return $ (if isTightList items then vcat else vsep) contents $$
            blankline
 blockToOrg (DefinitionList items) = do
   contents <- mapM definitionListItemToOrg items

test/writer.org

@@ -230,18 +230,14 @@ Multiple paragraphs:
    :PROPERTIES:
    :CUSTOM_ID: nested
    :END:
-
 - Tab
-
   - Tab
-
     - Tab
 
 Here's another:
 
 1. First
 2. Second:
-
    - Fee
    - Fie
    - Foe
@@ -264,7 +260,6 @@ Same thing but with paragraphs:
    :PROPERTIES:
    :CUSTOM_ID: tabs-and-spaces
    :END:
-
 - this is a list item indented with tabs
 
 - this is a list item indented with spaces
@@ -277,7 +272,6 @@ Same thing but with paragraphs:
    :PROPERTIES:
    :CUSTOM_ID: fancy-list-markers
    :END:
-
 2) [@2] begins with 2
 
 3) and now 3
@@ -286,25 +280,20 @@ Same thing but with paragraphs:
 
    4. [@4] sublist with roman numerals, starting with 4
    5. more items
-
       1) a subsublist
       2) a subsublist
 
 Nesting:
 
 1. Upper Alpha
-
    1. Upper Roman.
-
       6) [@6] Decimal start with 6
-
          3) [@3] Lower alpha with paren
 
 Autonumbering:
 
 1. Autonumber.
 2. More.
-
    1. Nested.
 
 Should not be a list item:
@@ -598,7 +587,6 @@ Ellipses...and...and....
   :PROPERTIES:
   :CUSTOM_ID: latex
   :END:
-
 - \cite[22-23]{smith.1899}
 - \(2+2=4\)
 - \(x \in y\)