vala 0.40.5 release.

Various improvements and bug fixes:

• Warn if --gir is used without --library [#708693]
• Report an error if rank attribute is required but was not found [#660991]
• scanner: Accept \R and \N escape sequences in regex literals [#749576]
• scanner: Accept backreferences \1 through \99 in regex literals [#728574]
• codegen:
  • Avoid critical in get_basic_type_info() when there is no signature [#729517]
  • Fix serializing multidimensional arrays [#735437]
  • Guard get_default_ref_sink_function() against null base-class
  • Respect cname ccode-attribute of lockable fields
  • Fix casting of length for "ref" array parameters
• codewriter: Add 'new' to symbols if needed to match the original source [#614686]
• girparser: Deal with missing "name" attribute by falling back on "c:type"
• girwriter: Drop errornous indent
• girwriter: Properly output variadic methods and use introspectable="0"
• genie: Add support for the \v escape character [#664689]
• genie: Add support for the \uXXXX escape sequence

Bindings:

• glib-2.0: Fix IConv.iconv() [#634753]
• gobject-2.0: Make constructor of ParamSpecBoxed public
• gstreamer: Cherry-pick some fixes from 0.42
• gtk+-3.0: Update to 3.22.30+21fddc39
• gtk+-4.0: Update to 3.93.0+3a860719
• javascriptcoregtk-4.0: buffer of String.get_utf8_cstring() is not "ref" [#788113]
• posix: Add missing cname = "int" to Posix.Signal enum
• sqlite3: Add additional constants for flags of Database.open_v2() [#795627]
• webkit2gtk-4.0: Cherry-pick some fixes from 0.42