Update target spec metadata of Arm64EC Windows and Trusty targets

[taiki-e]

Update outdated target spec metadata in the following targets.

• Arm64EC Windows (arm64ec-pc-windows-msvc) is "tier 2 without host tools" since Promote arm64ec-pc-windows-msvc to tier 2 #126039 and supports std since before that, but metadata currently says that is tier 3 and has unknown std support status.
• Trusty targets ({aarch64,armv7,x86_64}-unknown-trusty) support std since Add libstd support for Trusty targets #136842 (and I confirmed they can be compiled with -Zbuild-std=std), but metadata currently says that has no std support.

Mentioning @dpaoliello as arm64ec-pc-windows-msvc target-maintainer.
Mentioning @randomPoison @ahomescu as Trusty target maintainers.

[rustbot]

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[rustbot]

These commits modify compiler targets.
(See the Target Tier Policy.)

[nnethercote]

The code changes match the description and seem fine to me, but I am unfamiliar with these targets in general, so I will wait a day or two in case @dpaoliello/@randomPoison/@ahomescu have anything to add.

[randomPoison]

This looks good to me wrt the changes to the Trusty targets. I added std support a little while back but forgot to update the target definitions. Thanks for fixing this!