Add grpc-mojo 0.2.6

[nsalerni]

Adds grpc-mojo 0.2.6, the gRPC client and server runtime.

This is a follow-up to #317. That PR bundled five packages plus build-order changes; this one adds only grpc-mojo.

All sibling deps are now on the channel:

• mojo-net 0.2.6 (#343)
• protomojo 0.4.2 (#344)
• mojo-tls 0.3.2 (#349)
• mojo-http2 0.2.8 (#351)

Version	0.2.6
Source	https://github.com/nsalerni/grpc-mojo/tree/v0.2.6
Pin	a7944f897f189a652c7d29f462dcc61cfc5843c8
Artifacts	grpc.mojoc plus libgrpcstop signal shim
Sibling deps	mojo-net >=0.2.6,<0.3.0, mojo-http2 >=0.2.6,<0.3.0, mojo-tls >=0.3.2,<0.4.0, protomojo >=0.4.2,<0.5.0

Checklist

• Recipe specifies compatible MAX/Mojo (mojo-compiler >=1.0.0,<1.1.0)
• License file is packaged (license_file: LICENSE)
• Build number set to 0 (new package)
• N/A: bump build number

Please add the OK to test label. PR CI only runs when that label is present.

[nsalerni]

0.2.7 is now tagged and has a replacement recipe: #370 (gzip + zlib, sibling pins 0.2.7/0.4.3/0.3.3/0.2.9). Prefer #370 as the first publish; this 0.2.6 PR can stay as a fallback until the sibling bumps land.

[alisterburt]

thanks! #370 failing build