FRAMINGHAM — The state has rejected a plan to push off filling a $2.5 million hole in Framingham’s water and sewer enterprise funds that was meant to buy time for city councilors to fix structural issues leading to the deficit. The enterprise funds, which pay to run the city’s water and sewer services used by every Framingham resident, went deep in the red when businesses — which pay the largest share of fees — stopped using as much water amid pandemic-related shutdowns and restrictions. The state Division of Local Services recently told the city that if it wanted to send out certified third quarter tax bills by Dec. 31, the $2.5 million deficit had to be cured — quickly.