fix(kqp): allow null keys for stream join with secondary index

[ulya-sidorina]

No description provided.

[github-actions]

⚪ 2024-12-06 18:26:07 UTC Pre-commit check linux-x86_64-release-asan for dcf8e20 has started.
⚪ 2024-12-06 18:26:18 UTC Artifacts will be uploaded here
⚪ 2024-12-06 18:29:32 UTC ya make is running...
🟡 2024-12-06 20:07:02 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
15258	15185	0	21	6	46

🟢 2024-12-06 20:08:18 UTC Build successful.
🟢 2024-12-06 20:08:44 UTC ydbd size 4.9 GiB changed* by -64.5 KiB, which is <= 0 Bytes vs main: OK

ydbd size dash	main: 6b63b7d	merge: dcf8e20	diff	diff %
ydbd size	5 305 965 960 Bytes	5 305 899 960 Bytes	-64.5 KiB	-0.001%
ydbd stripped size	1 365 628 240 Bytes	1 365 606 160 Bytes	-21.6 KiB	-0.002%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}

[github-actions]

⚪ 2024-12-06 18:26:07 UTC Pre-commit check linux-x86_64-relwithdebinfo for dcf8e20 has started.
⚪ 2024-12-06 18:26:19 UTC Artifacts will be uploaded here
⚪ 2024-12-06 18:29:41 UTC ya make is running...
🟡 2024-12-06 20:00:36 UTC Some tests failed, follow the links below. Going to retry failed tests...

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
32717	29876	0	6	2721	114

⚪ 2024-12-06 20:03:18 UTC ya make is running... (failed tests rerun, try 2)
🟡 2024-12-06 20:16:00 UTC Some tests failed, follow the links below. Going to retry failed tests...

Test history | Ya make output | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
837 (only retried tests)	729	0	2	0	106

⚪ 2024-12-06 20:16:11 UTC ya make is running... (failed tests rerun, try 3)
🔴 2024-12-06 20:28:19 UTC Some tests failed, follow the links below.

Test history | Ya make output | Test bloat | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
635 (only retried tests)	528	0	1	0	106

🟢 2024-12-06 20:28:28 UTC Build successful.
🟢 2024-12-06 20:28:49 UTC ydbd size 2.5 GiB changed* by -35.5 KiB, which is <= 0 Bytes vs main: OK

ydbd size dash	main: 6b63b7d	merge: dcf8e20	diff	diff %
ydbd size	2 699 421 808 Bytes	2 699 385 480 Bytes	-35.5 KiB	-0.001%
ydbd stripped size	483 524 944 Bytes	483 518 032 Bytes	-6.8 KiB	-0.001%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}

[github-actions]

⚪ 2024-12-07 08:23:21 UTC Pre-commit check linux-x86_64-relwithdebinfo for aecadfc has started.
⚪ 2024-12-07 08:23:32 UTC Artifacts will be uploaded here
⚪ 2024-12-07 08:26:52 UTC ya make is running...
🟡 2024-12-07 09:26:44 UTC Some tests failed, follow the links below. Going to retry failed tests...

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
32717	29883	0	1	2722	111

⚪ 2024-12-07 09:29:25 UTC ya make is running... (failed tests rerun, try 2)
🟢 2024-12-07 09:41:49 UTC Tests successful.

Test history | Ya make output | Test bloat | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
692 (only retried tests)	585	0	0	0	107

🟢 2024-12-07 09:42:03 UTC Build successful.
🟢 2024-12-07 09:42:22 UTC ydbd size 2.5 GiB changed* by -35.5 KiB, which is <= 0 Bytes vs main: OK

ydbd size dash	main: 6b63b7d	merge: aecadfc	diff	diff %
ydbd size	2 699 421 808 Bytes	2 699 385 480 Bytes	-35.5 KiB	-0.001%
ydbd stripped size	483 524 944 Bytes	483 518 032 Bytes	-6.8 KiB	-0.001%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}

[github-actions]

⚪ 2024-12-07 08:23:35 UTC Pre-commit check linux-x86_64-release-asan for aecadfc has started.
⚪ 2024-12-07 08:23:46 UTC Artifacts will be uploaded here
⚪ 2024-12-07 08:27:12 UTC ya make is running...
🟡 2024-12-07 09:41:42 UTC Some tests failed, follow the links below. This fail is not in blocking policy yet

Test history | Ya make output | Test bloat

TESTS	PASSED	ERRORS	FAILED	SKIPPED	MUTED?
15258	15174	0	24	11	49

🟢 2024-12-07 09:43:01 UTC Build successful.
🟢 2024-12-07 09:43:30 UTC ydbd size 4.9 GiB changed* by -64.5 KiB, which is <= 0 Bytes vs main: OK

ydbd size dash	main: 6b63b7d	merge: aecadfc	diff	diff %
ydbd size	5 305 965 960 Bytes	5 305 899 960 Bytes	-64.5 KiB	-0.001%
ydbd stripped size	1 365 628 240 Bytes	1 365 606 160 Bytes	-21.6 KiB	-0.002%

^{*please be aware that the difference is based on comparing your commit and the last completed build from the post-commit, check comparation}