Produce release-notes for vXX.YY releases in the release script

Release script assumed that all versions followed ‘vXX.YYY’ format
which has been changed to ‘vXX.YY’ with the v19.21 release.  Update
the script to handle the new format as well as supporting patch
levels (even though those have never been used so far).

package/cut-a-release.sh

@@ -77,7 +77,7 @@ git format-patch -o "$tmp/$pkg/experimental" "$master".."$experimental" >/dev/nu
 echo "$version" >$tmp/$pkg/.version
 
 mkdir -- "$tmp/$pkg/release-notes"
-for tag in $(g tag | grep -o '^v[1-9][0-9]\.[0-9][0-9][0-9]$'); do
+for tag in $(git tag | grep -o '^v[1-9][0-9]\.[0-9][0-9].*'); do
 	git cat-file tag $tag | sed '1,/^$/d' >$tmp/$pkg/release-notes/$tag.txt
 done