generate: Use the C type name for callback types

We use the identifier for function pointer fields inside structures, but
for callbacks that have a C type, we should use the type name instead.
3 jobs for callback-ctype in 2 minutes and 48 seconds (queued for 4 seconds)
Status Name Job ID Coverage
  Check
passed flake8 #1519271

00:01:29

failed mypy #1519272
allowed to fail

00:01:53

passed reuse #1519273

00:02:47

 
Name Stage Failure
failed
mypy Check
gidocgen/gir/parser.py:968: error: Argument 1 to "set_version" of "GIRElement" has incompatible type "Optional[str]"; expected "str"
gidocgen/gir/parser.py:986: error: Argument "get_type" to "GType" has incompatible type "Optional[str]"; expected "str"
gidocgen/gir/parser.py:1008: error: Argument "name" to "Union" has incompatible type "Optional[str]"; expected "str"
gidocgen/gir/parser.py:1008: error: Argument "symbol_prefix" to "Union" has incompatible type "Optional[str]"; expected "str"
gidocgen/gir/parser.py:1008: error: Argument "ctype" to "Union" has incompatible type "Optional[str]"; expected "str"
gidocgen/gir/parser.py:1010: error: Argument 1 to "set_version" of "GIRElement" has incompatible type "Optional[str]"; expected "str"
gidocgen/utils.py:823: error: Need type annotation for 'found_programs' (hint: "found_programs: Dict[<type>, <type>] = ...")
Found 218 errors in 3 files (checked 17 source files)
Cleaning up file based variables
ERROR: Job failed: exit code 1