meson: update nlohmann subproject to 3.7.3

Bump nlohmann to version used in OpenBMC 2.8

Signed-off-by: Andrei Kartashev <a.kartashev@yadro.com>
Change-Id: I831be642aef217ccf8c6a0abb1f93efabcd98ac7
diff --git a/subprojects/nlohmann.wrap b/subprojects/nlohmann.wrap
index 12f174d..3c028c3 100644
--- a/subprojects/nlohmann.wrap
+++ b/subprojects/nlohmann.wrap
@@ -1,3 +1,3 @@
 [wrap-git]
-revision = d2dd27dc3b8472dbaa7d66f83619b3ebcd9185fe
+revision = e7b3b40b5a95bc74b9a7f662830a27c49ffc01b4
 url = https://github.com/nlohmann/json.git