ci: add build tag

[thinkerou]

jsoniter tag run unit test error:

=== RUN   TestContextRenderIndentedJSON
    context_test.go:757: 
        	Error Trace:	context_test.go:757
        	Error:      	Not equal: 
        	            	expected: "{\n    \"bar\": \"foo\",\n    \"foo\": \"bar\",\n    \"nested\": {\n        \"foo\": \"bar\"\n    }\n}"
        	            	actual  : "{\n    \"bar\": \"foo\",\n    \"foo\": \"bar\",\n    \"nested\": {\n    \"foo\": \"bar\"\n}\n}"
        	            	Diff:
        	            	--- Expected
        	            	+++ Actual
        	            	@@ -4,4 +4,4 @@
        	            	     "nested": {
        	            	-        "foo": "bar"
        	            	-    }
        	            	+    "foo": "bar"
        	            	 }
        	            	+}
        	Test:       	TestContextRenderIndentedJSON

details: json-iterator/go#564 and json-iterator/go#229

[codecov]

Codecov Report

Merging #3214 (b7173f4) into master (92dd245) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #3214   +/-   ##
=======================================
  Coverage   98.06%   98.06%           
=======================================
  Files          43       43           
  Lines        3148     3148           
=======================================
  Hits         3087     3087           
  Misses         48       48           
  Partials       13       13           

Flag	Coverage Δ
go-1.15	98.06% <ø> (ø)
go-1.16	98.03% <ø> (ø)
go-1.17	97.96% <ø> (ø)
go-1.18	97.96% <ø> (ø)
go_json	98.04% <ø> (?)
macos-latest	98.06% <ø> (ø)
nomsgpack	98.03% <ø> (ø)
ubuntu-latest	98.06% <ø> (ø)

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