[chore] update dependencies (#4468)

- github.com/ncruces/go-sqlite3
- codeberg.org/gruf/go-mempool
- codeberg.org/gruf/go-structr (changes related on the above) *
- codeberg.org/gruf/go-mutexes (changes related on the above) *

* this is largely just fiddling around with package internals in structr and mutexes to rely on changes in mempool, which added a new concurrency-safe pool

Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4468
Co-authored-by: kim <grufwub@gmail.com>
Co-committed-by: kim <grufwub@gmail.com>

vendor/github.com/ncruces/go-sqlite3/context.go

@@ -1,7 +1,6 @@
 package sqlite3
 
 import (
-	"encoding/json"
 	"errors"
 	"math"
 	"time"
@@ -173,21 +172,6 @@ func (ctx Context) ResultPointer(ptr any) {
 		stk_t(ctx.handle), stk_t(valPtr))
 }
 
-// ResultJSON sets the result of the function to the JSON encoding of value.
-//
-// https://sqlite.org/c3ref/result_blob.html
-func (ctx Context) ResultJSON(value any) {
-	err := json.NewEncoder(callbackWriter(func(p []byte) (int, error) {
-		ctx.ResultRawText(p[:len(p)-1]) // remove the newline
-		return 0, nil
-	})).Encode(value)
-
-	if err != nil {
-		ctx.ResultError(err)
-		return // notest
-	}
-}
-
 // ResultValue sets the result of the function to a copy of [Value].
 //
 // https://sqlite.org/c3ref/result_blob.html