RFR: 8375692: Hotspot container tests assert with non-ascii vendor name [v2]

[SendaoYan]

On Tue, 20 Jan 2026 16:57:26 GMT, Severin Gehwolf <sgehwolf at openjdk.org> wrote:

>> Please review this test-only fix. For non-ascii vendor strings the hotspot container tests fail in fastdebug because the encoding of the vendor string doesn't match. Full details in [JDK-8375471](https://bugs.openjdk.org/browse/JDK-8375471). In order to avoid the assert, the containers need to set to an UTF-8 encoding. This patch proposes to do so by setting `LANG=C.UTF-8`.
>> 
>> Thoughts?
>> 
>> **Testing:**
>> - [x] GHA
>> - [x] Linux container tests on cg v1 and cg v2 with a JDK build and vendor string `Foo bar öÜß` and fastdebug. All pass. Most failed before.
>
> Severin Gehwolf has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Update copyright year

LGTM

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Marked as reviewed by syan (Committer).

PR Review: https://git.openjdk.org/jdk/pull/29315#pullrequestreview-3685013389