Remove checksums of git sources

They are not constant across installations

Golden_Repo/e/ecoHMEM/ecoHMEM-1.0.5-gompi-2022a.eb

@@ -22,9 +22,7 @@ sources = [{
     },
 }]
 
-checksums = [
-    'c7f0293029f9492e7762d3c64a2b1e3612d16ffbe77c12905cb1742b69ad5bda',
-]
+checksums = [None]
 
 dependencies = [
     ('Boost', '1.79.0'),

Golden_Repo/f/Flexmalloc/Flexmalloc-16Jan24.ecoHMEM-GCCcore-11.3.0.eb

@@ -16,9 +16,7 @@ sources = [{
     },
 }]
 
-checksums = [
-    'ff108e32e2f292e094ba2921e4d97cede3b15d88f12d9893af388d9ec8406b65',
-]
+checksums = [None]
 
 dependencies = [
     ('memkind', '1.14.0', '', ('GCCcore', '11.3.0')),

Golden_Repo/m/mpc-allocator/mpc-allocator-0.2.ecoHMEM-GCCcore-11.3.0.eb

@@ -22,7 +22,7 @@ patches = [
 ]
 
 checksums = [
-    'b694e6337d817a0c7078b0bf9ce1d26f98402f184f251031cc403b3f4e7350a7',
+    None,
     # mpc_allocator_fix.patch
     '7489f3bd0e2e0b3cee99a4f5c6466f5383bd369bd960f6edc38b1e4d335774ed',
 ]