feat: add support for setting `runtime_variant` parameter

[kyujin-cho]

Requires lablup/backend.ai#2260 patch applied to Backend.AI Core. This PR updates service launcher to both support environment variable manipulation and runtime_variant setup. For more information about runtime_variant check our internal document.

Checklist: (if applicable)

• [ ] Mention to the original issue
• [ ] Documentation
• [x] Minium required manager version
• [x] Specific setting for review (eg., KB link, endpoint or how to setup)
• [ ] Minimum requirements to check during review
• [ ] Test case(s) to demonstrate the difference of before/after

[yomybaby]

Please resolve conflict and ci fail issue. @kyujin-cho

[github-actions[bot]]

Coverage report for ./react

St.:grey_question:	Category	Percentage	Covered / Total
🔴	Statements	2.67% (-0.01% 🔻)	141/5280
🔴	Branches	2.88% (-0.01% 🔻)	101/3512
🔴	Functions	1.54% (-0% 🔻)	27/1754
🔴	Lines	2.55% (-0.01% 🔻)	132/5179

Test suite run success

51 tests passing in 5 suites.

Report generated by 🧪jest coverage report action from 8bc537251e169ef9b1666a30459f96ec5328e1de

[lizable]

• #2472 👈
• main

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