[chore] update to modernc.org/sqlite v1.38.0 with our concurrency workaround (#4256)

see: https://gitlab.com/cznic/sqlite/-/tags/v1.38.0
Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4256
Co-authored-by: kim <grufwub@gmail.com>
Co-committed-by: kim <grufwub@gmail.com>

vendor/modernc.org/libc/tls_linux_amd64.go

@@ -0,0 +1,16 @@
+// Copyright 2025 The Libc Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package libc // import "modernc.org/libc"
+
+func TLSAlloc(p0 *TLS, p1 int) uintptr
+func TLSFree(p0 *TLS, p1 int)
+
+func tlsAlloc(tls *TLS, n int) uintptr {
+	return tls.Alloc(n)
+}
+
+func tlsFre(tls *TLS, n int) {
+	tls.Free(n)
+}