I'm currently scraping data from a spreadsheet with the following format:

Each financial year is separated by in the following way:

What I'd like to do is create an additional column to the left called 'Financial_Year' that takes the date from the relevant cell.
So I would like the df to look as follows:

My code thus far is like:
library(tidyverse)
library(dplyr)
library(XLConnect)
tmp = tempfile(fileext = ".xls")
download.file(url = "https://dmo.gov.uk/umbraco/surface/DataExport/GetDataExport?reportCode=D4L&exportFormatValue=xls¶meters=%26Financial%20Year%3D(All)", destfile = tmp, mode="wb")
holds <- readWorksheetFromFile(file = tmp, sheet=1) %>%
filter(across(everything(), ~!is.na(.)))
Does anyone have any advice on how to achieve the result? (file is quite large).
EDIT What I have been doing up till now, is downloading each year-long s/s individually, knitting them together, renaming columns and dropping various columns.