Fix one of upstream non-determinism, tracked here:

https://github.com/JuliaLang/julia/issues/34115
https://github.com/JuliaLang/julia/issues/25900


Patch by Nicoló Balzarotti <nicolo@nixo.xyz>.

--- a/base/loading.jl
+++ b/base/loading.jl
@@ -807,7 +807,10 @@
         path = normpath(joinpath(dirname(prev), _path))
     end
     if _track_dependencies[]
-        push!(_require_dependencies, (mod, path, mtime(path)))
+          push!(_require_dependencies,
+                (mod, path,
+                 haskey(ENV, "SOURCE_DATE_EPOCH") ?
+                 parse(Float64, ENV["SOURCE_DATE_EPOCH"]) : mtime(path)))
     end
     return path, prev
 end
idden' name='showmsg' value='1'/><select name='h' onchange='this.form.submit();'>
<option value='koszko' selected='selected'>koszko</option>
<option value='koszko-scripts'>koszko-scripts</option>
</select> <input type='submit' value='switch'/></form></td></tr>
<tr><td class='sub'>Wojtek's customized Guix</td><td class='sub right'></td></tr></table>
<table class='tabs'><tr><td>
<a href='/guix/about/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=d3281df55141583f9d08d713ad30718acd97c1c4'>refs</a><a class='active' href='/guix/log/README?showmsg=1'>log</a><a href='/guix/tree/README?id=d3281df55141583f9d08d713ad30718acd97c1c4'>tree</a><a href='/guix/commit/README?id=d3281df55141583f9d08d713ad30718acd97c1c4'>commit</a><a href='/guix/diff/README?id=d3281df55141583f9d08d713ad30718acd97c1c4'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/README'>
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<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
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<div class='path'>path: <a href='/guix/log/?id=d3281df55141583f9d08d713ad30718acd97c1c4&amp;showmsg=1'>root</a>/<a href='/guix/log/README?id=d3281df55141583f9d08d713ad30718acd97c1c4&amp;showmsg=1'>README</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/README?id=d3281df55141583f9d08d713ad30718acd97c1c4'>Collapse</a>)</th><th class='left'>Author</th></tr>
<tr class='logheader'><td><span title='2021-05-20 01:58:04 +0200'>2021-05-20</span></td><td class='logsubject'><a href='/guix/commit/README?id=c0087d33705f53cc3619a1a43a33602aaecc3a8b'>The #guix channel is hosted by Libera Chat.</a></td><td>Tobias Geerinckx-Rice</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
* README (Contact): Update network name.
* ROADMAP: Likewise.
* doc/contributing.texi (Contributing): Likewise.
* doc/guix.texi (After System Installation): Likewise.


</td></tr>
<tr class='logheader'><td><span title='2020-10-23 12:57:20 -0400'>2020-10-23</span></td><td class='logsubject'><a href='/guix/commit/README?id=b5aaa3a4fb985d21e21e2a67f48b52f13ebd4728'>doc: Update README.</a></td><td>Maxim Cournoyer</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
* README (Installation): Do not mention installing Guix from Git anymore.
(Building from Git): Add section.


</td></tr>
<tr class='logheader'><td><span title='2020-10-22 22:47:54 -0400'>2020-10-22</span></td><td class='logsubject'><a href='/guix/commit/README?id=503d2bfde08f9bf97bbf430516d2f19faedd4319'>README: Refer to the manual for building from Git.</a></td><td>Maxim Cournoyer</td></tr>
<tr class='nohover-highlight'><td/><td colspan='3' class='logmsg'>
* README (Installing Guix from Guix): Remove section.
(Installation): For installing from Git, refer to the "Building from Git"
section of the manual and suggest using './pre-inst-env guix pull' rather than
'make install' for installing Guix.


</td></tr>