etc: merge etcChecks into checks

The `activate-system` daemon will now run all the checks, which seems
like probably a good idea anyway?

modules/nix/default.nix

@@ -876,7 +876,7 @@ in
     #
     # TODO: Maybe this could use a more general file placement mechanism
     # to express that we want it deleted and know only one hash?
-    system.activationScripts.etcChecks.text = mkAfter ''
+    system.activationScripts.checks.text = mkAfter ''
       nixCustomConfKnownSha256Hashes=(
         # v0.33.0
         6787fade1cf934f82db554e78e1fc788705c2c5257fddf9b59bdd963ca6fec63

modules/services/activate-system/default.nix

@@ -65,7 +65,7 @@ in
           ln -sfn /run/current-system /nix/var/nix/gcroots/current-system
         fi
 
-        ${config.system.activationScripts.etcChecks.text}
+        ${config.system.activationScripts.checks.text}
         ${config.system.activationScripts.etc.text}
         ${config.system.activationScripts.keyboard.text}
       '';

modules/system/activation-scripts.nix

@@ -113,7 +113,6 @@ in
 
       ${cfg.activationScripts.preActivation.text}
 
-      ${cfg.activationScripts.etcChecks.text}
       ${cfg.activationScripts.createRun.text}
       ${cfg.activationScripts.checks.text}
       ${cfg.activationScripts.extraActivation.text}

modules/system/etc.nix

@@ -39,7 +39,7 @@ in
         '') etc}
       '';
 
-    system.activationScripts.etcChecks.text = ''
+    system.activationScripts.checks.text = mkAfter ''
       declare -A etcSha256Hashes=(
         ${concatMapStringsSep "\n  "
           (attr: