Use variant of heredoc without interpolation wherever possible

spec/ameba/rule/lint/unused_literal_spec.cr

@@ -5,10 +5,10 @@ module Ameba::Rule::Lint
     subject = UnusedLiteral.new
 
     it "passes if literals are used to assign" do
-      expect_no_issues subject, <<-CRYSTAL
+      expect_no_issues subject, <<-'CRYSTAL'
         a = 1
         b = "string"
-        g = "interp \#{string}"
+        g = "interp #{string}"
         h = <<-HEREDOC
           this is a heredoc
           HEREDOC
@@ -293,22 +293,22 @@ module Ameba::Rule::Lint
     # Locations for Regex literals were added in Crystal v1.15.0
     {% if compare_versions(Crystal::VERSION, "1.15.0") >= 0 %}
       it "fails if a regex literal is unused" do
-        expect_issue subject, <<-CRYSTAL
+        expect_issue subject, <<-'CRYSTAL'
           a = /hello world/
           /goodnight moon/
           # ^^^^^^^^^^^^^^ error: Literal value is not used
-          b = /goodnight moon, \#{a}/
-          /goodnight moon, \#{a}/
+          b = /goodnight moon, #{a}/
+          /goodnight moon, #{a}/
           # ^^^^^^^^^^^^^^^^^^^^ error: Literal value is not used
           CRYSTAL
       end
     {% else %}
       it "passes if a regex literal is unused" do
-        expect_no_issues subject, <<-CRYSTAL
+        expect_no_issues subject, <<-'CRYSTAL'
           a = /hello world/
           /goodnight moon/
-          b = /goodnight moon, \#{a}/
-          /goodnight moon, \#{a}/
+          b = /goodnight moon, #{a}/
+          /goodnight moon, #{a}/
           CRYSTAL
       end
     {% end %}

spec/ameba/rule/typing/method_parameter_type_restriction_spec.cr

@@ -164,10 +164,10 @@ module Ameba::Rule::Typing
           rule = MethodParameterTypeRestriction.new
           rule.default_value = true
 
-          expect_issue rule, <<-CRYSTAL
+          expect_issue rule, <<-'CRYSTAL'
             def hello(a = "world")
                     # ^ error: Method parameter should have a type restriction
-              "hello \#{a}"
+              "hello #{a}"
             end
             CRYSTAL
         end
@@ -187,10 +187,10 @@ module Ameba::Rule::Typing
         end
 
         it "fails if a block parameter with a name doesn't have a type restriction" do
-          expect_issue rule, <<-CRYSTAL
+          expect_issue rule, <<-'CRYSTAL'
             def hello(&a)
                      # ^ error: Method parameter should have a type restriction
-              "hello, \#{a.call}"
+              "hello, #{a.call}"
             end
             CRYSTAL
         end