fix: raw identifier in the schema string attribute

[Peefy]

1. Does this PR affect any open issues?(Y/N) and add issue references (e.g. "fix #123", "re #123".):

• N
• Y

• fix: raw identifier in the schema string attribute

2. What is the scope of this PR (e.g. component or file name):

• kclvm/sema/src/pre_process/identifier.rs

3. Provide a description of the PR(e.g. more details, effects, motivations or doc link):

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Other

4. Are there any breaking changes?(Y/N) and describe the breaking changes(e.g. more details, motivations or doc link):

• N
• Y

5. Are there test cases for these changes?(Y/N) select and add more details, references or doc links:

• Unit test
• Integration test
• Benchmark (add benchmark stats below)
• Manual test (add detailed scripts or steps below)
• Other

• kclvm/sema/src/pre_process/test_data/raw_identifier.k
• kclvm/sema/src/pre_process/tests.rs

[coveralls]

Pull Request Test Coverage Report for Build 7946181476

Details

• -3 of 15 (80.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.002%) to 72.3%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
kclvm/sema/src/pre_process/tests.rs	5	8	62.5%

Totals
Change from base Build 7946135307:	0.002%
Covered Lines:	43891
Relevant Lines:	60707

---

💛 - Coveralls

[zong-zhe]

LGTM