Add types for *_machine.kernel()

[mochaaP]

Describe the bug
*_machine.kernel() should be available since meson 1.2.0.

To Reproduce
Steps to reproduce the behavior:

1. Open meson.build in $EDITOR
2. Type host_machine.kernel()
3. See error

Additional context
https://mesonbuild.com/Reference-tables.html#kernel-names-since-120

[mochaaP]

diff --git a/src/libtypenamespace/addedData.csv b/src/libtypenamespace/addedData.csv
index eead38dd..f62a7e46 100644
--- a/src/libtypenamespace/addedData.csv
+++ b/src/libtypenamespace/addedData.csv
@@ -119,3 +119,4 @@ sourceset_module::source_set,0.51.0
 wayland_module::find_protocol,0.62.0
 wayland_module::scan_xml,0.62.0
 env::unset,1.4.0
+build_machine::kernel,1.2.0
diff --git a/src/libtypenamespace/methoddocs.def b/src/libtypenamespace/methoddocs.def
index 1c877ece..17d645e1 100644
--- a/src/libtypenamespace/methoddocs.def
+++ b/src/libtypenamespace/methoddocs.def
@@ -13,6 +13,8 @@ Returns a more specific CPU name, such as `i686`, `amd64`, etc.
 Returns the CPU family name. [This table](https://mesonbuild.com/Reference-tables.html#cpu-families) contains all known CPU families. These are guaranteed to continue working.
 @build_machine::endian:
 Returns `'big'` on big-endian systems and `'little'` on little-endian systems.
+@build_machine::kernel:
+Returns the native kernel name. [This table](https://mesonbuild.com/Reference-tables.html#kernel-names-since-120) lists all of the currently known Kernel names.
 @build_machine::system:
 Returns the operating system name. [This table](https://mesonbuild.com/Reference-tables.html#operating-system-names) lists all of the currently known Operating System names, these are guaranteed to continue working.
 @build_tgt::extract_all_objects:
diff --git a/src/libtypenamespace/methods.def b/src/libtypenamespace/methods.def
index 08029ed2..a85d035b 100644
--- a/src/libtypenamespace/methods.def
+++ b/src/libtypenamespace/methods.def
@@ -36,6 +36,10 @@ build_machine::endian:
   - args:
   - returns:
     - str
+build_machine::kernel:
+  - args:
+  - returns:
+    - str
 build_machine::system:
   - args:
   - returns: