fix(task): prevent runner interrupt leakage on JDK 8

[wuuJiawei]

Root cause

On JDK 8, a cancelled Channel.receive() can restore the interrupt flag on the scheduler worker. The task wrapper cleaned task state and context but left that flag set. When the worker was reused, the next channel wait immediately failed with CancelledException before the scope deadline fired. scope.await() then returned normally because deadlineTriggered was still false.

Fix

Clear the runner interrupt status in TaskExecution after execution cleanup, including the queued-task early-return path. This keeps cancellation observable inside the task while preventing interrupt state from leaking into the next task on a reused worker.

Added a deterministic regression test with an executor that intentionally retains worker interrupt state between commands.

Verification

• Local JDK 8: mvn -B -ntp clean verify, 618/618 passed
• Local JDK 17: mvn -B -ntp clean verify, 618/618 passed
• JDK 8 ChannelInterruptionTest: 50 rounds x 5 tests = 250 passes
• git diff --check: passed
• The pre-fix reproducer reached task=CANCELLED, token=false after a cancelled channel wait; the fixed test now consistently throws ScopeTimeoutException.

This PR is a follow-up to the already released v1.2.2 and should be released as the next patch version after merge.

[wuuJiawei]

1.2.3 final verification

PR #5 was merged and released as v1.2.3.

Verification	Result
PR CI core matrix	JDK 8 / 11 / 17 / 21 passed
Local JDK 8 mvn -B -ntp clean verify	618 tests, 0 failures/errors/skips
Local JDK 17 mvn -B -ntp clean verify	618 tests, 0 failures/errors/skips
Local JDK 17 mvn -B -ntp clean install	618 tests, 0 failures/errors/skips
Release deploy verification	618 tests, coverage gate passed, signing and Central validation passed
threadforge-slf4j	4 tests passed
threadforge-micrometer	1 test passed
Examples	4 sources compiled and packaged
Benchmarks	JMH shaded jar compiled and packaged
Regression target	ChannelInterruptionTest 5/5 passed on JDK 8 and JDK 17
Maven Central	pub.lighting:threadforge-core:1.2.3 jar and pom return HTTP 200
GitHub Release workflow	Success on JDK 21

Release: https://github.com/wuuJiawei/ThreadForge/releases/tag/v1.2.3

Maven Central: https://repo.maven.apache.org/maven2/pub/lighting/threadforge-core/1.2.3/