fix(tests): enable testing with Redis CE 8.0-M4 in CI (#3247)

* introduce github workflow for ci similar to the one in redis-py

use prerelease for 8.0-M4

* Enable osscluster tests in CI

* Add redis major version env

Enable filtering test per redis major version
Fix test for FT.SEARCH WITHSCORE, the default scorer
has changed.

fix Makefile syntax

remove filter from github action

fix makefile

use the container name in Makefile

* remove 1.20 from doctests

* self review, cleanup, add comments

* add comments, reorder prints, add default value for REDIS_MAJOR_VERSION

search_commands.go

@@ -282,23 +282,30 @@ type FTSearchSortBy struct {
 	Desc      bool
 }
 
+// FTSearchOptions hold options that can be passed to the FT.SEARCH command.
+// More information about the options can be found
+// in the documentation for FT.SEARCH https://redis.io/docs/latest/commands/ft.search/
 type FTSearchOptions struct {
-	NoContent       bool
-	Verbatim        bool
-	NoStopWords     bool
-	WithScores      bool
-	WithPayloads    bool
-	WithSortKeys    bool
-	Filters         []FTSearchFilter
-	GeoFilter       []FTSearchGeoFilter
-	InKeys          []interface{}
-	InFields        []interface{}
-	Return          []FTSearchReturn
-	Slop            int
-	Timeout         int
-	InOrder         bool
-	Language        string
-	Expander        string
+	NoContent    bool
+	Verbatim     bool
+	NoStopWords  bool
+	WithScores   bool
+	WithPayloads bool
+	WithSortKeys bool
+	Filters      []FTSearchFilter
+	GeoFilter    []FTSearchGeoFilter
+	InKeys       []interface{}
+	InFields     []interface{}
+	Return       []FTSearchReturn
+	Slop         int
+	Timeout      int
+	InOrder      bool
+	Language     string
+	Expander     string
+	// Scorer is used to set scoring function, if not set passed, a default will be used.
+	// The default scorer depends on the Redis version:
+	// - `BM25` for Redis >= 8
+	// - `TFIDF` for Redis < 8
 	Scorer          string
 	ExplainScore    bool
 	Payload         string