Add PostgreSQL 17 support

[Vonng]

Fail to build against PostgreSQL 17

cd '/home/vagrant/pigsty-deb/pg-savior/build/debian/postgresql-16-pg-savior/usr/lib/postgresql/16/lib/bitcode' && /usr/lib/llvm-16/bin/llvm-lto -thinlto -thinlto-action=thinlink -o pg_savior.index.bc pg_savior/pg_savior.bc
make[4]: Leaving directory '/home/vagrant/pigsty-deb/pg-savior/build'
# 16: make clean
make[4]: Entering directory '/home/vagrant/pigsty-deb/pg-savior/build'
rm -f pg_savior.so pg_savior.o  \
    pg_savior.bc
make[4]: Leaving directory '/home/vagrant/pigsty-deb/pg-savior/build'
### End 16 loop ###
### PostgreSQL 17 loop ###
# 17: make
make[4]: Entering directory '/home/vagrant/pigsty-deb/pg-savior/build'
gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Werror=vla -Wendif-labels -Wmissing-format-attribute -Wimplicit-fallthrough=3 -Wcast-function-type -Wshadow=compatible-local -Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard -Wno-format-truncation -Wno-stringop-truncation -g -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -fno-omit-frame-pointer -g -O2 -ffile-prefix-map=/home/vagrant/pigsty-deb/pg-savior/build=. -fstack-protector-strong -Wformat -Werror=format-security -fPIC -fvisibility=hidden -I. -I./ -I/usr/include/postgresql/17/server -I/usr/include/postgresql/internal  -Wdate-time -D_FORTIFY_SOURCE=2 -D_GNU_SOURCE -I/usr/include/libxml2   -c -o pg_savior.o pg_savior.c
pg_savior.c: In function ‘show_saved’:
pg_savior.c:171:3: warning: implicit declaration of function ‘tuplestore_donestoring’; did you mean ‘tuplestore_rescan’? [-Wimplicit-function-declaration]
  171 |   tuplestore_donestoring(tupstore);
      |   ^~~~~~~~~~~~~~~~~~~~~~
      |   tuplestore_rescan
gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Werror=vla -Wendif-labels -Wmissing-format-attribute -Wimplicit-fallthrough=3 -Wcast-function-type -Wshadow=compatible-local -Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard -Wno-format-truncation -Wno-stringop-truncation -g -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -fno-omit-frame-pointer -g -O2 -ffile-prefix-map=/home/vagrant/pigsty-deb/pg-savior/build=. -fstack-protector-strong -Wformat -Werror=format-security -fPIC -fvisibility=hidden pg_savior.o -L/usr/lib/x86_64-linux-gnu -Wl,-z,relro -Wl,-z,now -L/usr/lib/llvm-16/lib  -Wl,--as-needed -g -O2 -ffile-prefix-map=/home/vagrant/pigsty-deb/pg-savior/build=. -fstack-protector-strong -Wformat -Werror=format-security -fvisibility=hidden -shared -o pg_savior.so
/usr/bin/clang-16 -Wno-ignored-attributes -fno-strict-aliasing -fwrapv -fexcess-precision=standard -Xclang -no-opaque-pointers -Wno-unused-command-line-argument -Wno-compound-token-split-by-macro -O2  -I. -I./ -I/usr/include/postgresql/17/server -I/usr/include/postgresql/internal  -Wdate-time -D_FORTIFY_SOURCE=2 -D_GNU_SOURCE -I/usr/include/libxml2  -flto=thin -emit-llvm -c -o pg_savior.bc pg_savior.c
pg_savior.c:171:3: error: call to undeclared function 'tuplestore_donestoring'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
  tuplestore_donestoring(tupstore);
  ^
1 error generated.
make[4]: *** [/usr/lib/postgresql/17/lib/pgxs/src/makefiles/../../src/Makefile.global:1085: pg_savior.bc] Error 1
make[4]: Leaving directory '/home/vagrant/pigsty-deb/pg-savior/build'
### End 17 loop (FAILED with exit code 2) ###
make[3]: *** [debian/rules:18: override_dh_auto_install] Error 2
make[3]: Leaving directory '/home/vagrant/pigsty-deb/pg-savior/build'
make[2]: *** [debian/rules:24: binary] Error 2
make[2]: Leaving directory '/home/vagrant/pigsty-deb/pg-savior/build'
dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2
make[1]: *** [Makefile:17: build] Error 2
make[1]: Leaving directory '/home/vagrant/pigsty-deb/pg-savior'
make: *** [Makefile:209: pg_savior] Error 2