fix(source): injected source is not polled

[tabVersion]

Signed-off-by: tabVersion tabvision@bupt.icu

What's changed and what's your intention?

PLEASE DO NOT LEAVE THIS EMPTY !!!

Please explain IN DETAIL what the changes are in this PR and why they are needed:

in prev impl, injected source via channel is not handled synchronously, which results in changes are not applied but the barrier is delivered successfully.

in this pr, we use a oneshot channel to force applying changes synchronously

• Summarize your change (mandatory)
• How does this PR work? Need a brief introduction for the changed logic (optional)
• Describe clearly one logical change and avoid lazy messages (optional)
• Describe any limitations of the current code (optional)
• Add the 'user-facing changes' label if your PR contains changes that are visible to users (optional)

Checklist

• I have written necessary docs and comments
• I have added necessary unit tests and integration tests
• All checks passed in ./risedev check (or alias, ./risedev c)

Refer to a related PR or issue link (optional)

[codecov]

Codecov Report

Merging #3225 (50e9739) into main (ad2911d) will decrease coverage by 0.02%.
The diff coverage is 74.51%.

@@            Coverage Diff             @@
##             main    #3225      +/-   ##
==========================================
- Coverage   73.57%   73.55%   -0.03%     
==========================================
  Files         745      745              
  Lines      102290   101508     -782     
==========================================
- Hits        75261    74663     -598     
+ Misses      27029    26845     -184     

Flag	Coverage Δ
rust	73.55% <74.51%> (-0.03%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/batch/src/task/task_manager.rs	71.98% <0.00%> (ø)
src/bench/ss_bench/operations/get.rs	0.00% <0.00%> (ø)
...rc/bench/ss_bench/operations/prefix_scan_random.rs	0.00% <ø> (ø)
src/common/src/error.rs	64.81% <0.00%> (-1.36%)	⬇️
src/common/src/hash/key.rs	85.44% <ø> (ø)
src/common/src/lib.rs	100.00% <ø> (ø)
src/ctl/src/cmd_impl/hummock/list_kv.rs	0.00% <0.00%> (ø)
src/expr/src/expr/expr_unary.rs	72.10% <ø> (-2.55%)	⬇️
src/expr/src/vector_op/cast.rs	71.52% <ø> (+5.50%)	⬆️
src/frontend/src/handler/dml.rs	0.00% <0.00%> (ø)
... and 69 more

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[shanicky]

LGTM