[MM-50161] Update dependencies

[hanzei]

Summary

• 1d814d61e71971a2b31a6b54412f5c1e4332aa80: Update go dependencies
• c80228d6e84b821fc6410d1354d31e0cc883f4c8: Cleanup golangci-lint rule
• 93242cd723c0c00579989618bbbc7782c0b6bc05: Remove server/plugin_test.go. The tests in that file heavily rely on mocking and are brittle.
• c82509f3dea6d89e9ff5c868a648b41146d8c585: Bumped the MM server version to 7.7 and updated min_server_version accordingly.

Ticket Link

Fixes https://mattermost.atlassian.net/browse/MM-50161

[hanzei]

Yes, once v1.3.0 releases, we should update the MM version used in https://github.com/mattermost/mattermost-app-examples.

[codecov-commenter]

Codecov Report

Base: 20.74% // Head: 20.33% // Decreases project coverage by -0.41% :warning:

Coverage data is based on head (19c63c4) compared to base (c5f06ee). Patch has no changes to coverable lines.

:exclamation: Current head 19c63c4 differs from pull request most recent head 8e8c794. Consider uploading reports for the commit 8e8c794 to get more accurate results

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #449 +/- ## ========================================== - Coverage 20.74% 20.33% -0.41% ========================================== Files 80 78 -2 Lines 5366 5262 -104 ========================================== - Hits 1113 1070 -43 + Misses 4114 4062 -52 + Partials 139 130 -9 ``` | [Impacted Files](https://codecov.io/gh/mattermost/mattermost-plugin-apps/pull/449?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=mattermost) | Coverage Δ | | |---|---|---| | [server/main.go](https://codecov.io/gh/mattermost/mattermost-plugin-apps/pull/449?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=mattermost#diff-c2VydmVyL21haW4uZ28=) | | | | [server/plugin.go](https://codecov.io/gh/mattermost/mattermost-plugin-apps/pull/449?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=mattermost#diff-c2VydmVyL3BsdWdpbi5nbw==) | | | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=mattermost). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=mattermost)

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