[TEST] Skip new tests using ingnore_unavailable in BWC tests against 5.0.0

5.0.0 nodes don't understand these parameters and will throw an exception
if a 5.0.0 node will receive the request.

Relates to #21281

rest-api-spec/src/main/resources/rest-api-spec/test/indices.upgrade/10_basic.yaml

@@ -18,6 +18,9 @@
 
 ---
 "Upgrade indices ignore unavailable":
+  - skip:
+    version: " - 5.0.0"
+    reason: ignore_unavailable was added as a bugfix in 5.0.1 see #21281
 
   - do:
       indices.create:
@@ -40,6 +43,10 @@
 ---
 "Upgrade indices allow no indices":
 
+  - skip:
+    version: " - 5.0.0"
+    reason: ignore_unavailable was added as a bugfix in 5.0.1 see #21281
+
   - do:
       indices.upgrade:
         index: test_index
@@ -51,6 +58,10 @@
 ---
 "Upgrade indices disallow no indices":
 
+  - skip:
+    version: " - 5.0.0"
+    reason: ignore_unavailable was added as a bugfix in 5.0.1 see #21281
+
   - do:
       catch: missing
       indices.upgrade:
@@ -60,6 +71,11 @@
 
 ---
 "Upgrade indices disallow unavailable":
+
+  - skip:
+    version: " - 5.0.0"
+    reason: ignore_unavailable was added as a bugfix in 5.0.1 see #21281
+
   - do:
       indices.create:
         index: test_index