initialize libdash only on first call

[AnirudhNarsipur]

libdash.parser.parse takes in an init argument that indicates whether libdash should be initialized. This should be set to False after the first call. Not initializing libdash properly will call the following program to hang:

import libdash.parser


a = libdash.parser.parse("bad0.sh")
b = list(a)
c = libdash.parser.parse("bad0.sh")
d = list(c)

where bad0.sh is simply:

cat /a.txt

While I believe PaSH only calls libdash once it's better to be defensive.

[github-actions]

OS:ubuntu-20.04
Tue Nov 21 05:07:15 UTC 2023
intro: 2/2 tests passed.
interface: 41/41 tests passed.
compiler: 54/54 tests passed.

[github-actions]

OS:ubuntu-20.04
Tue Nov 21 05:08:37 UTC 2023
intro: 2/2 tests passed.
interface: 41/41 tests passed.
compiler: 54/54 tests passed.

[github-actions]

OS = Debian 10
CPU = Intel(R) Core(TM) i7-8700 CPU @ 3.20GHz
Ram = 15752
Hash = 3237ef4
Kernel= Linux 4.15.0-197-generic x86_64

benchmark	tests	passed	failed	untested	unresolved	unsupported	not_in_use	other_status
posix	494	375	41	31	6	40	1	0
intro	2	2	0	0	0	0	0	0
interface	41	41	0	0	0	0	0	0
compiler	54	54	0	0	0	0	0	0

[github-actions]

OS = Debian 10
CPU = Intel(R) Core(TM) i7-8700 CPU @ 3.20GHz
Ram = 15752
Hash = 9cf4d00
Kernel= Linux 4.15.0-197-generic x86_64

benchmark	tests	passed	failed	untested	unresolved	unsupported	not_in_use	other_status
posix	494	375	41	31	6	40	1	0
intro	2	2	0	0	0	0	0	0
interface	41	41	0	0	0	0	0	0
compiler	54	54	0	0	0	0	0	0

[angelhof]

Looks good to me! If I recall correctly we had discussed this in some meeting some time ago right? Feel free to merge from my side!