gi-docgen: upgrade 2023.1 -> 2023.3

gi-docgen: upgrade 2023.1 -> 2023.3

Changelog:
============
Fixed:
- Add missing dependency [#175]
- Add missing test data to the source archive
- Match dependencies list in the index and sidebar [!177]
- Use KeyboardEvent.key to focus search input [#151]
- Build fixes for subproject use [!185]
- Remove display:flex from headings [#147]
- Split transfer notes based on direction [#141]
- Clarify signal flags [!189]
- Hide build section if empty [#160]
- Always explicitely use utf-8 when reading/writing files [!193]
- use `color-scheme: dark` when in dark mode [!188]

Added:
- Use packaging module to properly compare versions
- Add "implements" in class definition pseudocode
- Ignore the first class instance struct field
- Parse default-value attribute [#103]
- Test the gtk-doc sigil parsing
- Support admonitions in docblocks [#170]
- Add link to the extra content files location in the source repository [#118]
- Search for GIR XML in `$GI_GIR_PATH` and `/usr/share/gir-1.0` [!196]
- Add fallback for missing "since" [!198]

Changed:
- Redesign the search results
- Redesign the index for enumeration types

Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>