HBASE-27913 Add 3.0.0-alpha-4 to download page (#5272)

Signed-off-by: Yulin Niu <niuyulin@apache.org>
diff --git a/src/site/xdoc/downloads.xml b/src/site/xdoc/downloads.xml
index 9ccbdab..8ed218e 100644
--- a/src/site/xdoc/downloads.xml
+++ b/src/site/xdoc/downloads.xml
@@ -45,24 +45,24 @@
     </tr>
     <tr>
       <td style="test-align: left">
-        3.0.0-alpha-3
+        3.0.0-alpha-4
       </td>
       <td style="test-align: left">
-        2022/06/27
+        2023/06/07
       </td>
       <td style="test-align: left">
-        <a href="https://downloads.apache.org/hbase/3.0.0-alpha-3/api_compare_2.0.0_to_3.0.0-alpha-3RC0.html">3.0.0-alpha-3 vs 2.0.0</a>
+        <a href="https://downloads.apache.org/hbase/3.0.0-alpha-4/api_compare_2.0.0_to_3.0.0-alpha-4RC0.html">3.0.0-alpha-4 vs 2.0.0</a>
       </td>
       <td style="test-align: left">
-        <a href="https://downloads.apache.org/hbase/3.0.0-alpha-3/CHANGES.md">Changes</a>
+        <a href="https://downloads.apache.org/hbase/3.0.0-alpha-4/CHANGES.md">Changes</a>
       </td>
       <td style="test-align: left">
-        <a href="https://downloads.apache.org/hbase/3.0.0-alpha-3/RELEASENOTES.md">Release Notes</a>
+        <a href="https://downloads.apache.org/hbase/3.0.0-alpha-4/RELEASENOTES.md">Release Notes</a>
       </td>
       <td style="test-align: left">
-        <a href="https://www.apache.org/dyn/closer.lua/hbase/3.0.0-alpha-3/hbase-3.0.0-alpha-3-src.tar.gz">src</a> (<a href="https://downloads.apache.org/hbase/3.0.0-alpha-3/hbase-3.0.0-alpha-3-src.tar.gz.sha512">sha512</a> <a href="https://downloads.apache.org/hbase/3.0.0-alpha-3/hbase-3.0.0-alpha-3-src.tar.gz.asc">asc</a>) <br />
-        <a href="https://www.apache.org/dyn/closer.lua/hbase/3.0.0-alpha-3/hbase-3.0.0-alpha-3-bin.tar.gz">bin</a> (<a href="https://downloads.apache.org/hbase/3.0.0-alpha-3/hbase-3.0.0-alpha-3-bin.tar.gz.sha512">sha512</a> <a href="https://downloads.apache.org/hbase/3.0.0-alpha-3/hbase-3.0.0-alpha-3-bin.tar.gz.asc">asc</a>) <br />
-        <a href="https://www.apache.org/dyn/closer.lua/hbase/3.0.0-alpha-3/hbase-3.0.0-alpha-3-client-bin.tar.gz">client-bin</a> (<a href="https://downloads.apache.org/hbase/3.0.0-alpha-3/hbase-3.0.0-alpha-3-client-bin.tar.gz.sha512">sha512</a> <a href="https://downloads.apache.org/hbase/3.0.0-alpha-3/hbase-3.0.0-alpha-3-client-bin.tar.gz.asc">asc</a>)
+        <a href="https://www.apache.org/dyn/closer.lua/hbase/3.0.0-alpha-4/hbase-3.0.0-alpha-4-src.tar.gz">src</a> (<a href="https://downloads.apache.org/hbase/3.0.0-alpha-4/hbase-3.0.0-alpha-4-src.tar.gz.sha512">sha512</a> <a href="https://downloads.apache.org/hbase/3.0.0-alpha-4/hbase-3.0.0-alpha-4-src.tar.gz.asc">asc</a>) <br />
+        <a href="https://www.apache.org/dyn/closer.lua/hbase/3.0.0-alpha-4/hbase-3.0.0-alpha-4-bin.tar.gz">bin</a> (<a href="https://downloads.apache.org/hbase/3.0.0-alpha-4/hbase-3.0.0-alpha-4-bin.tar.gz.sha512">sha512</a> <a href="https://downloads.apache.org/hbase/3.0.0-alpha-4/hbase-3.0.0-alpha-4-bin.tar.gz.asc">asc</a>) <br />
+        <a href="https://www.apache.org/dyn/closer.lua/hbase/3.0.0-alpha-4/hbase-3.0.0-alpha-4-client-bin.tar.gz">client-bin</a> (<a href="https://downloads.apache.org/hbase/3.0.0-alpha-4/hbase-3.0.0-alpha-4-client-bin.tar.gz.sha512">sha512</a> <a href="https://downloads.apache.org/hbase/3.0.0-alpha-4/hbase-3.0.0-alpha-4-client-bin.tar.gz.asc">asc</a>)
       </td>
       <td>
         Testing only, not production ready