go.mod, vendor: update (#3358)

* go.mod, vendor: remove unnecessary dependencies

Commands:
1. go mod tidy
2. go mod vendor

* go.mod, vendor: update cloud.google.com/go

Commands:
1. go get -u cloud.google.com/go
2. go mod tidy
3. go mod vendor

* go.mod, vendor: update cloud.google.com/*

Commands:
1. go get -u cloud.google.com/storage cloud.google.com/logging
2. go mod tidy
3. go mod vendor

* go.mod, .golangci.yml, vendor: update *lint*

Commands:
1. go get -u golang.org/x/tools github.com/golangci/golangci-lint@v1.47.0
2. go mod tidy
3. go mod vendor
4. edit .golangci.yml to suppress new errors (resolved in the same PR later)

* all: fix lint errors

hash.go: copy() recommended by gosimple
parse.go: ent is never nil
verifier.go: signal.Notify() with unbuffered channel is bad. Have no idea why.

* .golangci.yml: adjust godot rules

check-all is deprecated, but still work
if you're hesitating too - I'll remove this commit

1 files changed, 54 insertions, 0 deletions

diff --git a/vendor/github.com/hexops/gotextdiff/README.md b/vendor/github.com/hexops/gotextdiff/README.md
new file mode 100644
index 000000000..bfd49a0c9
--- /dev/null
+++ b/vendor/github.com/hexops/gotextdiff/README.md
@@ -0,0 +1,54 @@
+# gotextdiff - unified text diffing in Go <a href="https://hexops.com"><img align="right" alt="Hexops logo" src="https://raw.githubusercontent.com/hexops/media/master/readme.svg"></img></a>
+
+This is a copy of the Go text diffing packages that [the official Go language server gopls uses internally](https://github.com/golang/tools/tree/master/internal/lsp/diff) to generate unified diffs.
+
+If you've previously tried to generate unified text diffs in Go (like the ones you see in Git and on GitHub), you may have found [github.com/sergi/go-diff](https://github.com/sergi/go-diff) which is a Go port of Neil Fraser's google-diff-match-patch code - however it [does not support unified diffs](https://github.com/sergi/go-diff/issues/57).
+
+This is arguably one of the best (and most maintained) unified text diffing packages in Go as of at least 2020.
+
+(All credit goes to [the Go authors](http://tip.golang.org/AUTHORS), I am merely re-publishing their work so others can use it.)
+
+## Example usage
+
+Import the packages:
+
+```Go
+import (
+    "github.com/hexops/gotextdiff"
+    "github.com/hexops/gotextdiff/myers"
+)
+```
+
+Assuming you want to diff `a.txt` and `b.txt`, whose contents are stored in `aString` and `bString` then:
+
+```Go
+edits := myers.ComputeEdits(span.URIFromPath("a.txt"), aString, bString)
+diff := fmt.Sprint(gotextdiff.ToUnified("a.txt", "b.txt", aString, edits))
+```
+
+`diff` will be a string like:
+
+```diff
+--- a.txt
++++ b.txt
+@@ -1,13 +1,28 @@
+-foo
++bar
+```
+
+## API compatability
+
+We will publish a new major version anytime the API changes in a backwards-incompatible way. Because the upstream is not being developed with this being a public package in mind, API breakages may occur more often than in other Go packages (but you can always continue using the old version thanks to Go modules.)
+
+## Alternatives
+
+- [github.com/andreyvit/diff](https://github.com/andreyvit/diff): Quick'n'easy string diffing functions for Golang based on github.com/sergi/go-diff.
+- [github.com/kylelemons/godebug/diff](https://github.com/kylelemons/godebug/tree/master/diff): implements a linewise diff algorithm ([inactive](https://github.com/kylelemons/godebug/issues/22#issuecomment-524573477)).
+
+## Contributing
+
+We will only accept changes made [upstream](https://github.com/golang/tools/tree/master/internal/lsp/diff), please send any contributions to the upstream instead! Compared to the upstream, only import paths will be modified (to be non-`internal` so they are importable.) The only thing we add here is this README.
+
+## License
+
+See https://github.com/golang/tools/blob/master/LICENSE