Update the upload job (#3385)

Summary:
The current regex doesn't match as needed, but the corrected one does. Also exporting the GITHUB_REF variable just in case.

Pull Request resolved: #3385

Reviewed By: dbort

Differential Revision: D56659290

Pulled By: svekars

fbshipit-source-id: 19672df509656958e355d2a88c506cfe056649fd
(cherry picked from commit 9314595)

.github/workflows/doc-build.yml

@@ -94,11 +94,11 @@ jobs:
         # Get github.ref for the output doc folder. By default "main"
         # If matches a tag like refs/tags/v1.12.0-rc3 or
         # refs/tags/v1.12.0 convert to 1.12
-        GITHUB_REF=${{ github.ref }}
+        export GITHUB_REF=${{ github.ref }}
 
         # Convert refs/tags/v1.12.0rc3 into 1.12.
         # Adopted from https://github.com/pytorch/pytorch/blob/main/.github/workflows/_docs.yml#L150C11-L155C13
-        if [[ "${GITHUB_REF}" =~ ^refs/tags/v([0-9]+\\.[0-9]+)\\. ]]; then
+        if [[ "${GITHUB_REF}" =~ ^refs/tags/v([0-9]+\.[0-9]+) ]]; then
           TARGET_FOLDER="${BASH_REMATCH[1]}"
         else
           TARGET_FOLDER="main"