Always use line feed for newlines in acceptance tests (#2865)

## Why
Based on feedback in
#2720 (comment). We
should always treat new lines in acceptance tests in windows as `\n`.
This is important because the characters itself can be semantically
important in tests. For example, an additional `\r` character in windows
changes the upload payload if you are uploading the file's content to a
workspace.

## Tests
Existing workspace-io test should no longer need a custom override for
windows.

Author: shreyas-goenka

acceptance/.gitattributes

@@ -0,0 +1,5 @@
+# We should always treat new lines in text files acceptance tests in windows as \n.
+# This is important because the characters itself can be semantically important in tests.
+# For example, an additional \r character in windows changes the upload payload if you are
+# uploading the file's content to a workspace.
+*.txt text eol=lf

acceptance/selftest/record_cloud/workspace-file-io/test.toml

@@ -1,9 +1,4 @@
-# hello, world\n base64 encoded in unix
+# hello, world\n base64 encoded
 [[Repls]]
 Old = "aGVsbG8sIHdvcmxkCg=="
 New = "[HELLO-WORLD]"
-
-# hello, world\n base64 encoded in windows
-[[Repls]]
-Old = "aGVsbG8sIHdvcmxkDQo="
-New = "[HELLO-WORLD]"