Remove duplicate words (#4280)

* Remove duplicate the

* Remove duplicate that

Author: kamil-tekiela

reference/datetime/constants.xml

@@ -119,7 +119,7 @@
      <simpara>
       This format allows for year ranges outside of ISO-8601's normal range
       of <literal>0000</literal>-<literal>9999</literal> by always
-      including a sign character. It also addresses that that timezone part
+      including a sign character. It also ensures that the timezone part
       (<literal>+01:00</literal>) is compatible with ISO-8601.
      </simpara>
     </note>

reference/datetime/datetimeinterface.xml

@@ -212,7 +212,7 @@
        <simpara>
         This format allows for year ranges outside of ISO-8601's normal range
         of <literal>0000</literal>-<literal>9999</literal> by always
-        including a sign character. It also addresses that that timezone part
+        including a sign character. It also ensures that the timezone part
         (<literal>+01:00</literal>) is compatible with ISO-8601.
        </simpara>
       </note>

reference/filesystem/functions/dirname.xml

@@ -5,7 +5,7 @@
   <refname>dirname</refname>
   <refpurpose>Returns a parent directory's path</refpurpose>
  </refnamediv>
- 
+
  <refsect1 role="description">
   &reftitle.description;
   <methodsynopsis>
@@ -27,20 +27,20 @@
   </note>
   <caution>
    <para>
-    On Windows, <function>dirname</function> assumes the currently set codepage, so for it to see the 
-    correct directory name with multibyte character paths, the matching codepage must 
+    On Windows, <function>dirname</function> assumes the currently set codepage, so for it to see the
+    correct directory name with multibyte character paths, the matching codepage must
     be set.
     If <parameter>path</parameter> contains characters which are invalid for the
     current codepage, the behavior of <function>dirname</function> is undefined.
    </para>
    <para>
     On other systems, <function>dirname</function> assumes <parameter>path</parameter>
-    to be encoded in an ASCII compatible encoding. Otherwise the behavior of the
+    to be encoded in an ASCII compatible encoding. Otherwise, the behavior of
     the function is undefined.
    </para>
   </caution>
  </refsect1>
- 
+
  <refsect1 role="parameters">
   &reftitle.parameters;
   <para>