baggage.New panics on members with values including 0x80 char

[fabiobozzo]

Description

The validation rule for baggage key/values chars has a N+1 problem with the unicode value: 0x80.
For instance, baggage.NewMemberRaw could be called with a string value including the rune 128 and return no error, but panic.

=== RUN TestValidateValueChar
--- FAIL: TestValidateValueChar (0.00s)
panic: runtime error: index out of range [128] with length 128 [recovered]
panic: runtime error: index out of range [128] with length 128

Solution in: #5494 👈

Environment

• OS: any
• Architecture: any
• Go Version: 1.21+
• opentelemetry-go version: [v1.26.0, 59bbe11]

Steps To Reproduce

1. Call baggage.NewMemberRaw with a string (value, or key) including the 0x80 rune.
2. The new member is returned with no errors.
3. Call baggage.New with that member
4. validateValueChar in the downstream call stack panics because of an unsafe slice boundary check

Expected behavior

The creation of a baggage member having strings including the 0x80 char fails with an error, instead of panicking.

[MrAlias]

Closed by #5494