Fix typos found by codespell in ada

contrib/ada/readme.txt

@@ -8,7 +8,7 @@ It provides Ada-style access to the ZLib C library.
 
         Here are the main changes since ZLib.Ada 1.2:
 
-- Attension: ZLib.Read generic routine have a initialization requirement
+- Attention: ZLib.Read generic routine have a initialization requirement
   for Read_Last parameter now. It is a bit incompartible with previous version,
   but extends functionality, we could use new parameters Allow_Read_Some and
   Flush now.

contrib/ada/zlib-streams.ads

@@ -62,7 +62,7 @@ package ZLib.Streams is
                                     := Default_Buffer_Size;
       Write_Buffer_Size : in     Ada.Streams.Stream_Element_Offset
                                     := Default_Buffer_Size);
-   --  Create the Comression/Decompression stream.
+   --  Create the Compression/Decompression stream.
    --  If mode is In_Stream then Write operation is disabled.
    --  If mode is Out_Stream then Read operation is disabled.
 

contrib/ada/zlib.adb

@@ -204,7 +204,7 @@ package body ZLib is
       end if;
 
       --  We allow ZLib to make header only in case of default header type.
-      --  Otherwise we would either do header by ourselfs, or do not do
+      --  Otherwise we would either do header by ourselves, or do not do
       --  header at all.
 
       if Header = None or else Header = GZip then

contrib/ada/zlib.ads

@@ -114,7 +114,7 @@ package ZLib is
    -- Compression strategy constants --
    ------------------------------------
 
-   --  RLE stategy could be used only in version 1.2.0 and later.
+   --  RLE strategy could be used only in version 1.2.0 and later.
 
    Filtered         : constant Strategy_Type;
    Huffman_Only     : constant Strategy_Type;