Remove noexcept from to_file_time

d0355r3.html

@@ -2741,7 +2741,7 @@ in time, even though they may have different epochs.
 <pre>
 template &lt;class Duration&gt;
 file_time&lt;common_type_t&lt;Duration, seconds&gt;&gt;
-to_file_time(const utc_time&lt;Duration&gt;&amp; t) noexcept;
+to_file_time(const utc_time&lt;Duration&gt;&amp; t);
 </pre>
 <blockquote>
 <p>
@@ -2754,7 +2754,7 @@ in time, even though they may have different epochs.
 <pre>
 template &lt;class Duration&gt;
 file_time&lt;common_type_t&lt;Duration, seconds&gt;&gt;
-to_file_time(const tai_time&lt;Duration&gt;&amp; t) noexcept;
+to_file_time(const tai_time&lt;Duration&gt;&amp; t);
 </pre>
 <blockquote>
 <p>
@@ -2767,7 +2767,7 @@ in time, even though they may have different epochs.
 <pre>
 template &lt;class Duration&gt;
 file_time&lt;common_type_t&lt;Duration, seconds&gt;&gt;
-to_file_time(const gps_time&lt;Duration&gt;&amp; t) noexcept;
+to_file_time(const gps_time&lt;Duration&gt;&amp; t);
 </pre>
 <blockquote>
 <p>