[performance] bump codeberg.org/gruf/go-kv to v2 (#4341)

updates our codeberg.org/gruf/go-kv log key-value formatting library to latest version, which comes with some maaaaaaajor speed boosts in the form of:
- very minimal reflect.Value{} usage
- caching prepared formatting functions per type

~~still a work-in-progress until i make a release tag on the go-kv repository, which itself is waiting on published benchmark results in the README and finishing writing some code comments~~

benchmarks so far show this to be ~3x faster than the "fmt" stdlib package on average, when run across a wide variety (106 different types) of test cases, while still creating more visually friendly log output and actually recursing down nested struct ptrs

Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4341
Co-authored-by: kim <grufwub@gmail.com>
Co-committed-by: kim <grufwub@gmail.com>

testrig/util.go

@@ -31,8 +31,7 @@ import (
 	"code.superseriousbusiness.org/gotosocial/internal/messages"
 	"code.superseriousbusiness.org/gotosocial/internal/processing/workers"
 	"code.superseriousbusiness.org/gotosocial/internal/state"
-	"codeberg.org/gruf/go-byteutil"
-	"codeberg.org/gruf/go-kv/format"
+	"codeberg.org/gruf/go-kv/v2"
 )
 
 // Starts workers on the provided state using noop processing functions.
@@ -283,7 +282,7 @@ func WaitFor(condition func() bool) bool {
 
 // dump returns debug output of 'v'.
 func dump(v any) string {
-	var buf byteutil.Buffer
-	format.Append(&buf, v)
-	return buf.String()
+	var kv kv.Field
+	kv.V = v
+	return kv.Value(false)
 }