tests: Expanded linting tests for deprecations to cover str attribute in vars

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Signed-off-by: Ole Herman Schumacher Elgesem <ole@northern.tech>

Author: olehermanse

tests/lint/002_deprecations.expected.txt

@@ -4,9 +4,14 @@
   ^-------^
 Deprecation: Promise type 'defaults' is deprecated at tests/lint/002_deprecations.x.cf:3:3
 
+  vars:
+    "x" str => "value";
+        ^-^
+Deprecation: Use 'string' instead of 'str' at tests/lint/002_deprecations.x.cf:6:9
+
     "Hello, CFEngine"
       ifvarclass => "cfengine";
       ^--------^
-Deprecation: Use 'if' instead of 'ifvarclass' at tests/lint/002_deprecations.x.cf:7:7
-FAIL: tests/lint/002_deprecations.x.cf (2 errors)
-Failure, 2 errors in total.
+Deprecation: Use 'if' instead of 'ifvarclass' at tests/lint/002_deprecations.x.cf:9:7
+FAIL: tests/lint/002_deprecations.x.cf (3 errors)
+Failure, 3 errors in total.

tests/lint/002_deprecations.x.cf

@@ -2,6 +2,8 @@ bundle agent main
 {
   defaults:
     "x" string => "value";
+  vars:
+    "x" str => "value";
   reports:
     "Hello, CFEngine"
       ifvarclass => "cfengine";