Ignore extracted sqlite-rembed source directory

Add .gitignore pattern for deps/sqlite3/sqlite-rembed-*/ to prevent
accidental commit of extracted source code. The source is distributed
as sqlite-rembed-0.0.1-alpha.9.tar.gz and extracted during build.

Follows existing pattern for other extracted dependencies like
sqlite-amalgamation-*/.

.gitignore

@@ -115,6 +115,7 @@ deps/pcre/pcre-*/
 deps/prometheus-cpp/prometheus-cpp-*/
 deps/re2/re2-*/
 deps/sqlite3/sqlite-amalgamation-*/
+deps/sqlite3/sqlite-rembed-*/
 deps/coredumper/coredumper-*/
 deps/postgresql/postgresql-*/
 deps/postgresql/postgres-*/