Belatedly adding Paul Hargrove to the CONTRIBUTORS file (chapel-lang#26925)

[trivial, not reviewed]

Considering that the triaging he's been doing of GASNet portability
testing errors and reporting them counts as a contribution to the
release artifacts and its quality.

Author: bradcray

CONTRIBUTORS.md

@@ -14,6 +14,7 @@ Contributors to the Chapel 2.4 release
 * Lydia Duncan, [HPE]
 * Daniel Fedorin, [HPE]
 * Michael Ferguson, [HPE]
+* [Paul H. Hargrove], [Lawrence Berkeley National Laboratory]
 * Ben Harshbarger, [HPE]
 * John Hartman, [HPE]
 * Guillaume Helbecque, individual contributor
@@ -84,7 +85,6 @@ Contributors to previous releases
 * Rahul Ghangas, [GSoC 2020] student from [Australian National University]
 * Alexey Gokhberg, [Unicorn Enterprises SA]
 * Piyush Gupta, individual contributor
-* [Paul H. Hargrove], [Lawrence Berkeley National Laboratory]
 * Akihiro Hayashi, [Rice University]
 * Hannah Hemmaplardh, [Cray Inc.] intern from [University of Washington]
 * Steven Hemmy, [Cray Inc.] intern from [University of Wisconsin]