doc: remove extra quotes in generated docs

Commit a38edab (Makefile: generate doc versions via GIT-VERSION-GEN,
2024-12-06) moved these variables from the Makefile to asciidoc.conf.in.
When doing so, some extraneous quotes were added; these are visible in
the generated .xml files, at least, and possibly in other locations:

    --- a/tmp/orig-git-bisect.xml
    +++ b/Documentation/git-bisect.xml
    @@ -5,14 +5,14 @@
     <refentry lang="en">
     <refentryinfo>
	 <title>git-bisect(1)</title>
    -    <date>2024-12-06</date>
    -<revhistory><revision><date>2024-12-06</date></revision></revhistory>
    +    <date>'2024-12-06'</date>^M
    +<revhistory><revision><date>'2024-12-06'</date></revision></revhistory>^M
     </refentryinfo>
     <refmeta>
     <refentrytitle>git-bisect</refentrytitle>
     <manvolnum>1</manvolnum>
    -<refmiscinfo class="source">Git 2.47.1.409.g9bb10d27e7</refmiscinfo>
    -<refmiscinfo class="manual">Git Manual</refmiscinfo>
    +<refmiscinfo class="source">'Git 2.47.1.410.ga38edab7c8'</refmiscinfo>^M
    +<refmiscinfo class="manual">'Git Manual'</refmiscinfo>^M
     </refmeta>
     <refnamediv>
	 <refname>git-bisect</refname>

Signed-off-by: Kyle Lippincott <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: spectral54

Documentation/asciidoc.conf.in

@@ -21,9 +21,9 @@ tilde=~
 apostrophe='
 backtick=`
 litdd=--
-manmanual='Git Manual'
-mansource='Git @GIT_VERSION@'
-revdate='@GIT_DATE@'
+manmanual=Git Manual
+mansource=Git @GIT_VERSION@
+revdate=@GIT_DATE@
 
 ifdef::backend-docbook[]
 [linkgit-inlinemacro]